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A Self-Trapping, Bipolar Viologen Bromide Electrolyte for Aqueous Redox Flow Batteries

A Self-Trapping, Bipolar Viologen Bromide Electrolyte for Aqueous Redox Flow Batteries

09/06/2020

Tianbiao Liu, Wenda Wu, Jian Luo, Fang Wang, Bing Yuan. Aqueous organic redox flow batteries (AORFBs) have become increasing attractive for scalable energy storage. However, it remains challenging to develop high voltage, powerful AORFBs because of the

Dibridged, Monobridged, Vinylidene-Like, and Linear Structures for the Alkaline Earth Dihydrides Be2H2, Mg2H2, Ca2H2, Sr2H2, and Ba2H2. Proposals for Observations

Dibridged, Monobridged, Vinylidene-Like, and Linear Structures for the Alkaline Earth Dihydrides Be2H2, Mg2H2, Ca2H2, Sr2H2, and Ba2H2. Proposals for Observations

07/16/2020

Alexander I. Boldyrev, Nikolay V. Tkachenko. This research reports a search for peculiar monobridged structures of the E2H2 molecules (E = Be, Mg, Ca, Sr, Ba). For Be2H2 and Mg2H2, the monobridged geometry is not an equilibrium but rather a transition s

Comparison of Accelerated Solvent Extraction (ASE) and Energized Dispersive Guided Extraction (EDGE) for the analysis of pesticides in leaves

Comparison of Accelerated Solvent Extraction (ASE) and Energized Dispersive Guided Extraction (EDGE) for the analysis of pesticides in leaves

07/16/2020

Kimberly J. Hageman, Ashlie D. Kinross, Alexandria L. Foster. Various techniques have been evaluated for the extraction and cleanup of pesticides from environmental samples. In this work, a Selective Pressurized Liquid Extraction (SPLE) method for pesti

Label-free discrimination and quantitative analysis of oxidative stress induced cytotoxicity and potential protection of antioxidants using Raman micro-spectroscopy and machine learning

Label-free discrimination and quantitative analysis of oxidative stress induced cytotoxicity and potential protection of antioxidants using Raman micro-spectroscopy and machine learning

07/12/2020

Cheng-Wei Tom Chang. Diesel exhaust particles (DEPs) are major constituents of air pollution and associated with numerous oxidative stress-induced human diseases. In vitro toxicity studies are useful for developing a better understanding of species-spec

Amphiphilic aminoglycosides with increased selectivity for inhibition of connexin 43 (Cx43) hemichannels

Amphiphilic aminoglycosides with increased selectivity for inhibition of connexin 43 (Cx43) hemichannels

07/12/2020

Cheng-Wei T. Chang, Yagya P. Subedi, Paul Roberts, Heath Montgomery, Noah Thakeray. Gap junction channels formed by the association of connexin hemichannels play a crucial role in intercellular communication. Connexin 43 (Cx43) is expressed in a variety

The ditetrel bond: noncovalent bond between neutral tetrel atoms

The ditetrel bond: noncovalent bond between neutral tetrel atoms

07/10/2020

Steve Scheiner. The ability of a tetrel atom to serve in the capacity of electron donor in a σ-hole noncovalent bond is tested by quantum calculations. The donor molecule TMH3 contains a metal atom M on a tetravalent tetrel (T) atom, with M = Li, Na, K

σ‐Aromaticity‐Induced Stabilization of Heterometallic Supertetrahedral Clusters [Zn6Ge16]4– and [Cd6Ge16]4–

σ‐Aromaticity‐Induced Stabilization of Heterometallic Supertetrahedral Clusters [Zn6Ge16]4– and [Cd6Ge16]4–

06/30/2020

Alexander I. Boldyrev, Ivan Popov, Nikolay V. Tkachenko. In this work, the largest heterometallic supertetrahedral clusters, [Zn6Ge16]4– and [Cd6Ge16]4–, were directly self‐assembled through highly‐charged [Ge4]4– units and transition metal cations, in

Complexes of HArF and AuX (X = F, Cl, Br, I). Comparison of H‐bonds, halogen bonds, F‐shared bonds and covalent bonds

Complexes of HArF and AuX (X = F, Cl, Br, I). Comparison of H‐bonds, halogen bonds, F‐shared bonds and covalent bonds

06/22/2020

Steve Scheiner. The various sorts of complexes in which HArF and AuX (X = F, Cl, Br, I) can engage are probed by MP2/aug‐cc‐pVTZ calculations. The most weakly bound are those containing a halogen bond (XB) of the AuX⋯FArH sort, with binding energies less...

Novel Noncompetitive Type Three Secretion System ATPase Inhibitors Shut Down Shigella Effector Secretion

Novel Noncompetitive Type Three Secretion System ATPase Inhibitors Shut Down Shigella Effector Secretion

06/22/2020

Nicholas E. Dickenson, Heather B. Case. Shigella is the causative agent of bacillary dysentery and is responsible for an estimated 165 million infections and 600,000 deaths annually. Like many Gram-negative pathogens, Shigella relies on a type three sec

Interface Catalysts of Ni/Co2N for Hydrogen Electrochemistry

Interface Catalysts of Ni/Co2N for Hydrogen Electrochemistry

06/05/2020

Yi Rao, Kaixi Sun, Tong Zhang, Liming Tan, Yuqin Qian, Jeremy Shaw.

Coordination of a Central Atom by Multiple Intramolecular Pnicogen Bonds

Coordination of a Central Atom by Multiple Intramolecular Pnicogen Bonds

06/04/2020

Steve Scheiner. A central pnicogen Z atom (Z = Sb, As) is covalently attached to the O atom of three −O(CH2)nX chains where X represents either an aldehyde or amine group. The chain can fold around so that the basic X group can engage in a noncovalent p

A robust ionic liquid magnesium electrolyte enabling Mg/S batteries

A robust ionic liquid magnesium electrolyte enabling Mg/S batteries

05/29/2020

T. Leo Liu, Yujing Bi, Shuijian He, Chuanbin Fan, Jian Luo. Mg batteries are attractive for low-cost and sustainable energy storage because Mg as an anode material is highly abundant in the crust of the Earth, it has a high charge capacity (2205 Ah kg−1

Pnicogen Bonds Pairing Anionic Lewis Acid with Neutral and Anionic Bases

Pnicogen Bonds Pairing Anionic Lewis Acid with Neutral and Anionic Bases

05/26/2020

Steve Scheiner. The complexation process between anionic ZCl4– (Z = P, As, Sb) and neutral NCH and pyridine, as well as the CN– anion, is studied in both the gas phase and aqueous solution by high-level ab initio calculations. Despite the absence of a p

Influence of Adjuvants on Pesticide Soil–Air Partition Coefficients: Laboratory Measurements and Predicted Effects on Volatilization

Influence of Adjuvants on Pesticide Soil–Air Partition Coefficients: Laboratory Measurements and Predicted Effects on Volatilization

05/21/2020

Kimberly J. Hageman. A solid-phase fugacity meter was used to measure the soil–air partition coefficients of three semivolatile pesticides (chlorpyrifos, pyrimethanil, and trifluralin) in the absence of additional adjuvants (Ksoil–air,AI), as part of co

N3-Ligated nickel(ii) diketonate complexes: synthesis, characterization and evaluation of O2 reactivity

N3-Ligated nickel(ii) diketonate complexes: synthesis, characterization and evaluation of O2 reactivity

05/19/2020

Lisa M. Berreau, Josiah G. D. Elsberg. Interest in O2-dependent aliphatic carbon–carbon (C–C) bond cleavage reactions of first row divalent metal diketonate complexes stems from the desire to further understand the reaction pathways of enzymes such as D

All-metal σ-antiaromaticity in dimeric cluster anion {[CuGe9Mes]2}4−

All-metal σ-antiaromaticity in dimeric cluster anion {[CuGe9Mes]2}4−

05/11/2020

Alexander I. Boldyrev, Nikolay V. Tkachenko. In this work, we report a dimeric cluster anion, {[CuGe9Mes]2}4−, which was isolated as the [K(2,2,2-crypt)]+ salt and characterized by using single-crystal X-ray diffraction and ESI mass spectroscopy. The tit...

Rapid Antarctic ice sheet retreat under low atmospheric CO2

Rapid Antarctic ice sheet retreat under low atmospheric CO2

05/01/2020

Kimberly J. Hageman. Over the last 5 Million years, outstanding warm interglacial periods (i.e. 'super-interglacials') occurred under low atmospheric CO2 levels that may feature extensive Antarctica ice sheet collapse. Here, we focus on the extreme supe

CO Sense and Release Flavonols: Progress toward the Development of an Analyte Replacement PhotoCORM for Use in Living Cells

CO Sense and Release Flavonols: Progress toward the Development of an Analyte Replacement PhotoCORM for Use in Living Cells

04/23/2020

Lisa M. Berreau, Tatiana Soboleva, Marina Popova, Abby D. Benninghoff. Carbon monoxide (CO) is a signaling molecule in humans. Prior research suggests that therapeutic levels of CO can have beneficial effects in treating a variety of physiological and pa...

Modeling the Alkaline Hydrolysis of Diaryl Sulfate Diesters: A Mechanistic Study

Modeling the Alkaline Hydrolysis of Diaryl Sulfate Diesters: A Mechanistic Study

04/20/2020

Alvan C. Hengge. Phosphate and sulfate esters have important roles in regulating cellular processes. However, while there has been substantial experimental and computational investigation of the mechanisms and the transition states involved in phosphate

Anion⋅⋅⋅Anion Attraction in Complexes of MCl3− (M=Zn, Cd, Hg) with CN−

Anion⋅⋅⋅Anion Attraction in Complexes of MCl3− (M=Zn, Cd, Hg) with CN−

04/14/2020

Steve Scheiner. High‐level ab initio calculations show that the MCl3− anions comprising Group 2B M atoms Zn, Cd, and Hg form a stable complex with the CN− anion, despite the like charge of the two ions. The complexation occurs despite a negative π‐hole r...

Boron‐Made N2: Realization of a B≡B Triple Bond in the B2Al3− Cluster

Boron‐Made N2: Realization of a B≡B Triple Bond in the B2Al3− Cluster

04/06/2020

Alexander I. Boldyrev, Nikita Fedik, Ivan Popov. Until now, all B≡B triple bonds have been achieved by adopting two ligands in the L→B≡B←L manner. Herein, we report an alternative route of designing the B≡B bonds based on the assumption that by acquirin

On the Stability of Interactions between Pairs of Anions – Complexes of MCl3− (M=Be, Mg, Ca, Sr, Ba) with Pyridine and CN−

On the Stability of Interactions between Pairs of Anions – Complexes of MCl3− (M=Be, Mg, Ca, Sr, Ba) with Pyridine and CN−

03/23/2020

Steve Scheiner. The ability of the central M atom of the MCl3− anion, with M=Be, Mg, Ca, Sr, Ba, to engage in a noncovalent bond with an approaching nucleophile is gauged by ab initio methods. The N atom of pyridine forms a M⋅⋅⋅N bond with an interactio

Reduction of Substrates by Nitrogenases

Reduction of Substrates by Nitrogenases

03/16/2020

Lance C. Seefeldt, Zhi-Yong Yang, Derek F. Harris. Nitrogenase is the enzyme that catalyzes biological N2 reduction to NH3. This enzyme achieves an impressive rate enhancement over the uncatalyzed reaction. Given the high demand for N2 fixation to suppo

Stability, electronic, and optical properties of two‐dimensional phosphoborane

Stability, electronic, and optical properties of two‐dimensional phosphoborane

03/16/2020

Alexander I. Boldyrev, Nikolay V. Tkachenko. The structure and properties of two‐dimensional phosphoborane sheets were computationally investigated using Density Functional Theory calculations. The calculated phonon spectrum and band structure point to

σ-Aromaticity in the MoS2 Monolayer

σ-Aromaticity in the MoS2 Monolayer

02/23/2020

Alexander I. Boldyrev, Maksim Kulichenko. Molybdenum disulfide is a prominent semiconductor that received a lot of attention recently due to its unique properties. Possessing a layered crystal structure, one can tune the band gap from indirect to direct

How Many Pnicogen Bonds can be Formed to a Central Atom Simultaneously?

How Many Pnicogen Bonds can be Formed to a Central Atom Simultaneously?

02/13/2020

Steve Scheiner. A central ZF3 molecule (Z = P, As, Sb, Bi) is allowed to interact with a number of nucleophiles exemplified by NCH, NH3, and NC– anion. The Z···N pnicogen bond (ZB) to a single base grows stronger for heavier Z atom: P < A < Sb < Bi and

Interface-Specific Two-Dimensional Electronic Sum Frequency Generation Spectroscopy

Interface-Specific Two-Dimensional Electronic Sum Frequency Generation Spectroscopy

02/11/2020

Yi Rao, Gang-Hua Deng, Yuqin Qian, Qianshun Wei, Tong Zhang. High even-order surface/interface specific spectroscopy has the potential to provide more structural and dynamical information about surfaces and interfaces. In this work, we developed a novel

Ni-Catalyzed Electrochemical C(sp2)−C(sp3) Cross-Coupling Reactions

Ni-Catalyzed Electrochemical C(sp2)−C(sp3) Cross-Coupling Reactions

02/07/2020

T. Leo Liu, Jian Luo, Bo Hu, Wenda Wu, Maowei Hu. Nickel (Ni) catalyzed carbon-carbon (C−C) cross-coupling has been considerably developed in last decades and has demonstrated unique reactivities compared to palladium. However, existing Ni catalyzed cr

Selective Inhibition of Different Isoforms of Connexin Hemichannels by New Aminoglycosides

Selective Inhibition of Different Isoforms of Connexin Hemichannels by New Aminoglycosides

02/07/2020

Cheng-Wei T. Chang, Yagya P. Subedi, Madher N. AlFindee. Connexins hemichannels (HCs) from adjacent cells form gap-junctional channels that mediate cell-to-cell communication. Abnormal opening of “free” undocked HCs can produce cell damage and particip

Xe⋯chalcogen aerogen bond. Effect of substituents and size of chalcogen atom

Xe⋯chalcogen aerogen bond. Effect of substituents and size of chalcogen atom

02/03/2020

Steve Scheiner. The aerogen bond between the Xe and chalcogen atoms in complexes pairing XeOF2 with R1YR2 is examined by ab initio calculations for Y = O, S, and Se. In addition to HYH, one or both H atoms are changed to F or methyl groups. The interact

Competition between Intra and Intermolecular Triel Bonds. Complexes between Naphthalene Derivatives and Neutral or Anionic Lewis Bases

Competition between Intra and Intermolecular Triel Bonds. Complexes between Naphthalene Derivatives and Neutral or Anionic Lewis Bases

02/01/2020

Steve Scheiner. : A TrF2 group (Tr = B, Al, Ga, In, Tl) is placed on one of the α positions of naphthalene, and its ability to engage in a triel bond (TrB) with a weak (NCH) and strong (NC−) nucleophile is assessed by ab initio calculations. As a competi...

Can aromaticity be a kinetic trap? Example of mechanically interlocked aromatic [2-5]catenanes built from cyclo[18]carbon

Can aromaticity be a kinetic trap? Example of mechanically interlocked aromatic [2-5]catenanes built from cyclo[18]carbon

01/28/2020

Alexander I. Boldyrev, Nikita Fedik, Maksim Kulichenko. The unusual stability of cyclo[18]carbon arising from its aromaticity might be used to provide the kinetic trapping needed in the design of interlocked systems. The kinetic barrier separating the i

Dominant negative effects by inactive Spa47 mutants inhibit T3SS function and Shigella virulence

Dominant negative effects by inactive Spa47 mutants inhibit T3SS function and Shigella virulence

01/24/2020

Nicholas E. Dickenson, Heather B. Case. Type three secretion systems (T3SS) are complex nano-machines that evolved to inject bacterial effector proteins directly into the cytoplasm of eukaryotic cells. Many high-priority human pathogens rely on one or m

Toward understanding molecular recognition between protein arginine methyltransferases (PRMTs) and their substrates.

Toward understanding molecular recognition between protein arginine methyltransferases (PRMTs) and their substrates.

01/23/2020

Joan M. Hevel, Owen M. Price. Protein arginine methylation is a widespread eukaryotic posttranslational modification that occurs with as much frequency as ubiquitinylation. Yet how the nine different human protein arginine methyltransferases (PRMTs) reco...

Anisotropic Geminate and Non-Geminate Recombination of Triplet Excitons in Singlet Fission of Single Crystalline Hexacene

Anisotropic Geminate and Non-Geminate Recombination of Triplet Excitons in Singlet Fission of Single Crystalline Hexacene

01/23/2020

Jian Han, Qing Xie, Ganghua Deng, Yuqin Qian, Yi Rao. Singlet fission is known to improve solar energy utilization by circumventing the Shockley-Queisser thermodynamic limit. Understanding of triplet exciton generated by singlet fission is essential for

Dawn of Calcium Batteries

Dawn of Calcium Batteries

01/21/2020

Kevin V. Nielson, T. Leo Liu. Calcium batteries are a potentially sustainable, high‐energy‐density battery technology beyond Li ion batteries. Now the development of Ca batteries has become possible with a newly invented Ca electrolyte capable of revers

Periodic F-defects on the MgO surface as potential single-defect catalysts with non-linear optical properties

Periodic F-defects on the MgO surface as potential single-defect catalysts with non-linear optical properties

01/20/2020

Alexander I. Boldyrev, Maksim Kulichenko, Nikita Fedik. Single-atom catalysis is the ultimate approach in catalysis science which implies the utilization of a catalyst is as efficient as it gets. In this paper we suggest a new type of a single-atom (or

In-Situ Sulfurized Carbon-confined Cobalt for Long-Life Mg/S Batteries

In-Situ Sulfurized Carbon-confined Cobalt for Long-Life Mg/S Batteries

01/10/2020

Tianbiao Liu, Yujing Bi, Jian Luo. Magnesium (Mg) batteries have attracted growing attention owing to their low cost and high volumetric capacity. Mg/S batteries are of particular interest because of the high capacities of Mg and sulfur, which cooperati

Folding of the Transmembrane 25-Residues Influenza A M2 and Ala-25 Peptides

Folding of the Transmembrane 25-Residues Influenza A M2 and Ala-25 Peptides

01/08/2020

Steve Scheiner. The correct balance between hydrophobic London dispersion (LD) and peptide hydrogen bonding interactions must be attained for proteins to fold correctly. To investigate these important contributors we sought a comparison of the influenza

Erratum: High-resolution ENDOR spectroscopy combined with quantum chemical calculations reveals the structure of nitrogenase janus intermediate E4(4H)

Erratum: High-resolution ENDOR spectroscopy combined with quantum chemical calculations reveals the structure of nitrogenase janus intermediate E4(4H)

01/01/2020

Lance C. Seefeldt. The bond lengths for E4(4H)(a) listed in Figure 3 are incorrect. The corrected figure and caption are shown here (see the original Article for the cited references). (Figure presented) Figure 3. Lowest-energy structures of the Janus i

o-Quinone phenalenyl derivatives as expedient ligands for the design of magnetically active metal complexes: A computational study

o-Quinone phenalenyl derivatives as expedient ligands for the design of magnetically active metal complexes: A computational study

12/30/2019

Alexander I. Boldyrev. The DFT calculations of the electronic structure, energy characteristic and spin densities of cobalt(II) diketonate adducts with polycyclic triangular hydrocarbons functionalized with o-benzoquinone groups aimed at search for spin

Expansion of aromaticity magnetic criteria on multi‐layer structures. Magnetic response and spherical aromaticity of Matryoshka‐like [Sn@Cu12@Sn20]12‐ cluster

Expansion of aromaticity magnetic criteria on multi‐layer structures. Magnetic response and spherical aromaticity of Matryoshka‐like [Sn@Cu12@Sn20]12‐ cluster

12/22/2019

Alexander I. Boldyrev, Maksim Kulichenko, Nikita Fedik. The structural characterization of the discrete [Sn@Cu12@Sn20]12‐ cluster exposes a fascinating architecture composed by three‐concentric structural layers given by an endohedral Sn atom enclosed i

Understanding Trends in Pesticide Volatilization from Agricultural Fields Using the Pesticide Loss via Volatilization Model

Understanding Trends in Pesticide Volatilization from Agricultural Fields Using the Pesticide Loss via Volatilization Model

12/20/2019

Kimberly J. Hageman, Sean M. Lyons. The Pesticide Loss via Volatilization model was developed to predict and understand pesticide volatilization rates from a planted agricultural field. The model allows the user to adjust the properties of the pesticide

Spherical aromaticity of all‐metal [Bi@In8Bi12]3‐/5‐ clusters

Spherical aromaticity of all‐metal [Bi@In8Bi12]3‐/5‐ clusters

12/18/2019

Alexander I. Boldyrev_Nikolay V. Tkachenko. The chemical bonding of Zintl clusters is still an evolving and hot topic in the modern chemistry. In this paper we synthesized a novel [K([2.2.2]crypt)]4[In8Bi13] complex in a condensed phase. The quantum che

A Type IV-A CRISPR-Cas System in Pseudomonas aeruginosa Mediates RNA-Guided Plasmid Interference In Vivo

A Type IV-A CRISPR-Cas System in Pseudomonas aeruginosa Mediates RNA-Guided Plasmid Interference In Vivo

12/16/2019

Ryan N. Jackson, Valerie M. Crowley, Hannah N. Taylor, Josie Metcalf. Bacteria and archaea use CRISPR-Cas adaptive immune systems to destroy complementary nucleic acids using RNAs derived from CRISPR loci. Here, we provide the first functional evidence

Electronic structure and magnetic properties of the triangular nanographenes with radical substituents: a DFT study

Electronic structure and magnetic properties of the triangular nanographenes with radical substituents: a DFT study

12/11/2019

Alexander I. Boldyrev. A series of neutral triangular polycyclic aromatic hydrocarbons functionalized with various radical groups (dithiadiazolyl, verdazyl, nitronylnitroxyl, tert-butyl-nitroxyl and also (2,2,6,6-tetramethylpiperidin-1-yl)oxyl) has been

Coordination of anions by noncovalently bonded σ-hole ligands

Coordination of anions by noncovalently bonded σ-hole ligands

12/10/2019

Steve Scheiner. Research on σ-hole interactions that include halogen, chalcogen, pnicogen, and tetrel bonding has been accelerating in recent years. These cousins of the H-bond have many similar properties, including geometric preferences and energetics

Tuning the Competition between Hydrogen and Tetrel Bonds by a Magnesium Bond

Tuning the Competition between Hydrogen and Tetrel Bonds by a Magnesium Bond

12/04/2019

Steve Scheiner. A computational study of the complexes formed by TF3OH (T=C, Si, Ge) with three nitrogen‐containing bases NCH, NH3, and imidazole (IM) is carried out at the MP2/aug‐cc‐pVTZ level. TF3OH can participate in two different types of noncovale

Reversible Electrochemical Interface of Mg Metal and Conventional Electrolyte Enabled by Intermediate Adsorption

Reversible Electrochemical Interface of Mg Metal and Conventional Electrolyte Enabled by Intermediate Adsorption

12/04/2019

Tianbiao Leo Liu. Conventional electrolytes made by mixing simple Mg2+ salts and aprotic solvents, analogous to those in Li-ion batteries, are incompatible with Mg anodes because Mg metal readily reacts with such electrolytes, producing a passivation la

Exploring the limits of electronic transmutation: Ab initio study of LinBen (n = 3–5)

Exploring the limits of electronic transmutation: Ab initio study of LinBen (n = 3–5)

12/03/2019

Alexander I. Boldyrev, Jared K. Olson, Katie A. Lundell. We report the results obtained via ab initio studies for electronic transmutation of beryllium to boron. According to the electronic transmutation concept, an element Z, by acquiring an extra elec

Southern Ocean temperature records and ice-sheet models demonstrate rapid Antarctic ice sheet retreat under low atmospheric CO2 during Marine Isotope Stage 31

Southern Ocean temperature records and ice-sheet models demonstrate rapid Antarctic ice sheet retreat under low atmospheric CO2 during Marine Isotope Stage 31

11/28/2019

Kimberly J. Hageman. Over the last 5 million years, the Earth’s climate has oscillated between warm (interglacial) and cold (glacial) states. Some particularly warm interglacial periods (i.e. ‘super-interglacials’) occurred under low atmospheric CO2 and

The Hydrogen Bond: A Hundred Years and Counting

The Hydrogen Bond: A Hundred Years and Counting

11/18/2019

Steve Scheiner. Since its original inception, a great deal has been learned about the nature, properties, and applications of the H-bond. This review summarizes some of the unexpected paths that inquiry into this phenomenon has taken researchers. The tr

The flexible N-terminus of BchL protects its [4Fe-4S] cluster in oxygenic environments and autoinhibits activity

The flexible N-terminus of BchL protects its [4Fe-4S] cluster in oxygenic environments and autoinhibits activity

11/12/2019

Lance C. Seefeldt. The dark-operative protochlorophyllide oxidoreductase (DPOR) enzyme contains two [4Fe-4S]- containing component proteins (BchL and BchNB) that assemble in an ATP-dependent fashion to coordinate electron transfer and reduction of proto

Structures and energetics of clusters surrounding diatomic anions stabilized by hydrogen, halogen, and other noncovalent bonds

Structures and energetics of clusters surrounding diatomic anions stabilized by hydrogen, halogen, and other noncovalent bonds

11/11/2019

Steve Scheiner. Diatomic anions CN–, NO–, and OH– are surrounded by 2, 3, and 4 ligand molecules drawn from the HF, HCl, XF, YF2, ZF3, TF4, and TrF3 set wherein X = Cl, Br, Y = S, Se, Z = P, As, T = Si, Ge, and Tr = Al, Ga. In the case of two ligands, b

An Alternative and Facile Synthetic Approach for the Precursors of 3- and 6-Aminosugar Donors and Study of One-pot Glycosyltrasferation

An Alternative and Facile Synthetic Approach for the Precursors of 3- and 6-Aminosugar Donors and Study of One-pot Glycosyltrasferation

11/08/2019

Cheng-Wei Tom Chang, Uddav Pandey, Yagya Prasad Subedi, Madher N. Alfindee, Taylor Shepherd. 3- and 6-aminosugars are common motifs in bioactive compounds playing pivotal roles in the bioactivity of the core molecules to which they are attached. Howev

An Efficient Viologen-Based Electron Donor to Nitrogenase

An Efficient Viologen-Based Electron Donor to Nitrogenase

11/04/2019

Lance C. Seefeldt, T. Leo Liu, Artavazd Badalyan, Zhi-Yong Yang, Bo Hu, Jian Luo, Maowei Hu. Nitrogenase catalyzes the reduction of N2 to NH3, supporting all biological nitrogen fixation. Electron donors to this enzyme are ferredoxin or flavodoxin (in v

Computational Prediction of the Low-Temperature Ferromagnetic Semiconducting 2D SiN Monolayer

Computational Prediction of the Low-Temperature Ferromagnetic Semiconducting 2D SiN Monolayer

10/30/2019

Alexander I. Boldyrev. Nikolay V. Tkachenko. Since the discovery of graphene, 2D materials have captured the minds of scientists because of their attractive and unique electronic properties. In particular, magnetic 2D materials have become a subjec

Fate of the organophosphate insecticide, chlorpyrifos, in leaves, soil, and air following application

Fate of the organophosphate insecticide, chlorpyrifos, in leaves, soil, and air following application

10/24/2019

Kimberly J. Hageman. A field study was conducted to further our understanding about the fate and transport of the organophosphate insecticide, chlorpyrifos, and its degradation product, chlorpyrifos oxon. Leaf, soil and air sampling was conducted for 2

Rapid and direct measurement of methyltransferase activity in about 30 min

Rapid and direct measurement of methyltransferase activity in about 30 min

10/07/2019

Joan M. Hevel. Owen M. Price. Protein arginine methylation is a widespread eukaryotic posttranslational modification that occurs to both histone and non-histone proteins. The S-adenosyl-L-methionine (AdoMet or SAM)-dependent modification is catalyzed by t...

Extracellular vs Instracellular Delivery of CO: Does It Matter for a Stable, Diffusible Gasotransmitter?

Extracellular vs Instracellular Delivery of CO: Does It Matter for a Stable, Diffusible Gasotransmitter?

10/02/2019

Lisa M. Berreau, Tatiana Soboleva, Casey R. Simons Carbon monoxide (CO) is a gasotransmitter produced in humans. An essential unanswered question in the design of carbon monoxide releasing molecules (CORMs) is whether the delivery molecule should be lo

Establishing a Thermodynamic Landscape for the Active Site of Mo-Dependent Nitrogenase

Establishing a Thermodynamic Landscape for the Active Site of Mo-Dependent Nitrogenase

10/02/2019

Lance C. Seefeldt, Zhi-Yong Yang. Nitrogenase enzymes are the only biological catalysts able to convert N2 to NH3. Molybdenum-dependent nitrogenase consists of two proteins and three metallocofactors that sequentially shuttle eight electrons between thr

Anisotropic Singlet Fission in Single Crystalline Hexacene

Anisotropic Singlet Fission in Single Crystalline Hexacene

09/27/2019

Yi Rao, Gang-Hua Deng, Xia Li, Yuqin Qian. Singlet fission is known to improve solar energy utilization by circumventing the Shockley-Queisser limit. The two essential steps of singlet fission are the formation of a correlated triplet pair and its subse

Time-Resolved EPR Study of H2 Reductive Elimination from the Photoexcited Nitrogenase Janus E4(4H) Intermediate

Time-Resolved EPR Study of H2 Reductive Elimination from the Photoexcited Nitrogenase Janus E4(4H) Intermediate

09/24/2019

Lance C. Seefeldt. Nitrogenase is activated for N2 reduction through the accumulation of four reducing equivalents at the active-site FeMo-cofactor (FeMo-co: Fe7S9MoC; homocitrate) to form the key Janus intermediate, denoted E4(4H), whose lowest-energy

Definition of the chalcogen bond

Definition of the chalcogen bond

09/20/2019

Steve Scheiner. This recommendation proposes a definition for the term “chalcogen bond”; it is recommended the term is used to designate the specific subset of inter- and intramolecular interactions formed by chalcogen atoms wherein the Group 16 elemen

Manganese Catalyzed Desaturation of N-acyl Amines and Ethers

Manganese Catalyzed Desaturation of N-acyl Amines and Ethers

09/18/2019

Gang Li. Enamines and enol ethers are versatile synthons for chemical synthesis. While several methods have been developed to access such molecules, prefunctionalized starting materials are usually required and direct desaturation methods remain rare. Her...

Theoretical Studies of IR and NMR Spectral Changes Induced by Sigma-Hole Hydrogen, Halogen, Chalcogen, Pnicogen, and Tetrel Bonds in a Model Protein Environment

Theoretical Studies of IR and NMR Spectral Changes Induced by Sigma-Hole Hydrogen, Halogen, Chalcogen, Pnicogen, and Tetrel Bonds in a Model Protein Environment

09/12/2019

Steve Scheiner. Various types of σ-hole bond complexes were formed with FX, HFY, H2FZ, and H3FT (X = Cl, Br, I; Y = S, Se, Te; Z = P, As, Sb; T = Si, Ge, Sn) as Lewis acid. In order to examine their interactions with a protein, N-methylacetamide (NMA)

Chalcogen bonding of two ligands to hypervalent YF4 (Y = S, Se, Te, Po)

Chalcogen bonding of two ligands to hypervalent YF4 (Y = S, Se, Te, Po)

09/04/2019

Steve Scheiner. The ability of two NH3 ligands to engage in simultaneous chalcogen bonds to a hypervalent YF4 molecule, with Y = S, Se, Te, Po, is assessed via quantum calculations. The complex can take on one of two different geometries. The cis struc

Phthalate esters in biota, air and water in an agricultural area of western China, with emphasis on bioaccumulation and human exposure

Phthalate esters in biota, air and water in an agricultural area of western China, with emphasis on bioaccumulation and human exposure

09/02/2019

Kimberly J. Hageman, Ming-Jing He. Phthalate esters (PAEs) have been shown to be ubiquitous in abiotic and biotic environmental compartments; however, information about bioaccumulation behavior and human exposure, both via environmental exposure and th

Redox switchable catalysis utilizing a fluorescent dye

Redox switchable catalysis utilizing a fluorescent dye

08/28/2019

Casey R. Simons. This report describes the implementation of a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dye into the ligand framework of a Rh-based catalyst. The redox-active nature of the BODIPY dye is utilized to generate a catalyst that is

Spectroscopic Description of the E1 State of Mo Nitrogenase Based on Mo and Fe X-ray Absorption and Mossbauer Studies

Spectroscopic Description of the E1 State of Mo Nitrogenase Based on Mo and Fe X-ray Absorption and Mossbauer Studies

08/23/2019

Lance C. Seefeldt, Zhi-Yong Yang. Mo nitrogenase (N2ase) utilizes a two-component protein system, the catalytic MoFe and its electron-transfer partner FeP, to reduce atmospheric dinitrogen (N2) to ammonia (NH3). The FeMo cofactor contained in the MoFe p

Scalable and cost-effective tosylation-mediated synthesis of antifungal and fungal diagnostic 6"-Modified amphiphilic kanamycins

Scalable and cost-effective tosylation-mediated synthesis of antifungal and fungal diagnostic 6"-Modified amphiphilic kanamycins

08/21/2019

Cheng-Wei Tom Chang, Yagya Prasad Subedi, Uddav Pandey, Madher N. Alfindee Amphiphilic kanamycins bearing hydrophobic modifications at the 6″ position have attracted interest due to remarkable antibacterial-to-antifungal switches in bioactivity. In this

Realization of Lewis Basic Sodium Anion in the NaBH3- Cluster

Realization of Lewis Basic Sodium Anion in the NaBH3- Cluster

08/19/2019

Alexander I. Boldyrev, Nikita Fedik. We report a Na:- -->!B dative bond in the NaBH3- cluster, which was designed on the principle of minimum energy rupture, prepared by laser vaporization, and characterized by a synergy of anion photoelectron spectro

Superoctahedral two-dimensional metallic boron with peculiar magnetic properties

Superoctahedral two-dimensional metallic boron with peculiar magnetic properties

08/15/2019

Alexander I. Boldyrev, Nikolay V. Tkachenko, Nikita Fedik. Among the diversity of new materials, two-dimensional crystal structures have been attracting significant attention from the broad scientific community due to their promising applications in na

Theoretical insight into a feasible strategy of capturing, storing and releasing toxic HCN at the surface of doped BN-sheets by charge modulation

Theoretical insight into a feasible strategy of capturing, storing and releasing toxic HCN at the surface of doped BN-sheets by charge modulation

08/15/2019

Steve Scheiner, Tapas Kar. The response of boron nitride nanosheets (BNNSs), with the chemical composition of B25N25H20, serving as an adsorbent of toxic hydrogen cyanide (HCN) is explored by using density functional theory (M06-2X variant of DFT). Atom

Phototrophic N2 and CO2 Fixation Using a <i>Rhodopseudomonas palustris</i>-H2 Mediated Electrochemical System With Infrared Photons

Phototrophic N2 and CO2 Fixation Using a Rhodopseudomonas palustris-H2 Mediated Electrochemical System With Infrared Photons

08/14/2019

Scott A. Ensign, Lance C. Seefeldt, Mathangi Soundararajan A promising approach for the synthesis of high value reduced compounds is to couple bacteria to the cathode of an electrochemical cell, with delivery of electrons from the electrode driving red

Status and Prospects of Organic Redox Flow Batteries toward Sustainable Energy Storage

Status and Prospects of Organic Redox Flow Batteries toward Sustainable Energy Storage

08/12/2019

T. Leo Liu, Jian Luo, Bo Hu, Maowei Hu. Redox flow batteries (RFBs) are regarded a promising technology for large-scale electricity energy storage to realize efficient utilization of intermittent renewable energy. Redox-active materials are the most im

A Strategic High Yield Synthesis of 2,5-Dihydroxy-1,4-benoquinone Based MOFs

A Strategic High Yield Synthesis of 2,5-Dihydroxy-1,4-benoquinone Based MOFs

08/07/2019

T. Leo Liu, Kevin V. Nielson, Liping Zhang. Metal organic frameworks (MOFs) of the type NBu4M(DHBQ)1.5 (M = Ni2+, Fe2+, and Co2+; DHBQ = 2,5- dihydroxy-1,4-benzoquinone) were prepared with improved yield up to 100% via a simple benchtop aqueous additio

Retardation of Crystallization through the Addition of Dairy Phospholipids

Retardation of Crystallization through the Addition of Dairy Phospholipids

08/05/2019

Casey Simons. The objective of this work was to identify the effects that milk phospholipids (PL) have on crystallization of anhydrous milk fat (AMF). Three mixtures were prepared by adding 0%, 0.01%, and 0.1% PL to AMF. Each mixture was crystallized fo

Vibronic fingerprint of singlet fission in hexacene

Vibronic fingerprint of singlet fission in hexacene

08/05/2019

Yi Rao, Gang-Hua Deng, Qianshun Wei, Jian Han, Yuqin Qian. Singlet fission has the great potential to overcome the Shockley–Queisser thermodynamic limit and thus promotes solar power conversion efficiency. However, the current limited understandings of

A pH-Neutral, Metal-Free Aqueous Organic Redox Flow Battery Employing an Ammonium Anthrquinone Anolyte

A pH-Neutral, Metal-Free Aqueous Organic Redox Flow Battery Employing an Ammonium Anthrquinone Anolyte

08/05/2019

T. Leo Liu, Maowei Hu, Bo Hu, Jian Luo. Redox-active anthraquinone molecules represent promising anolyte materials in aqueous organic redox flow batteries (AORFBs). However, the chemical stability issue and corrosion nature of anthraquinone-based anoly

Chronic Toxicities of Neonicotinoids to Nymphs of the Common New Zealand Mayfly <i>Deleatidium</i> spp.

Chronic Toxicities of Neonicotinoids to Nymphs of the Common New Zealand Mayfly Deleatidium spp.

08/02/2019

Kimberly J. Hageman, Robert E. Alumbaugh, Sean M. Lyons. Neonicotinoid insecticides have been shown to have high chronic toxicity relative to acute toxicity, and therefore short‐term toxicity tests ≤96 h in duration may underestimate their environmental

Effects of Halogen, Chalcogen, Pnicogen, and Tetrel Bonds on IR and NMR Spectra

Effects of Halogen, Chalcogen, Pnicogen, and Tetrel Bonds on IR and NMR Spectra

08/02/2019

Steve Scheiner, Jia Lu. Complexes were formed pairing FX, FHY, FH2Z, and FH3T (X = Cl, Br, I; Y = S, Se, Te; Z = P, As, Sb; T = Si, Ge, Sn) with NH3 in order to form an A⋯N noncovalent bond, where A refers to the central atom. Geometries, energetics, at

Violation of Electrostatic Rules: Shifting the Balance between Pnicogen Bonds and Lone Pair−π Interactions Tuned by Substituents

Violation of Electrostatic Rules: Shifting the Balance between Pnicogen Bonds and Lone Pair−π Interactions Tuned by Substituents

08/01/2019

Steve Scheiner. Complexes were formed by pairing ZCl3 (Z = P, As, or Sb) with C2R4 (R = H, F, or CN). The first interaction present is a pnicogen bond between the Z atom and the C═C π-bond. This bond weakens as the H atoms of ethylene are replaced by el

New ideas from an old concept: the hydrogen bond

New ideas from an old concept: the hydrogen bond

08/01/2019

Steve Scheiner. Ongoing studies of the hydrogen bond (HB), in which a hydrogen (H) atom acts as a bridge between a pair of chemical groups, continues to offer new ideas about this interaction that have applications to biochemical processes. The ability

Current-use pesticides in New Zealand streams: Comparing results from grab samples and three types of passive samplers

Current-use pesticides in New Zealand streams: Comparing results from grab samples and three types of passive samplers

07/26/2019

Kimberly J. Hageman. New Zealand uses more than a ton of pesticides each year; many of these are mobile, relatively persistent, and can make their way into waterways. While considerable effort goes into monitoring nutrients in agricultural streams and

Electrocatalytic N2 Reduction to NH3 Using Enzyme Nitrogenase

Electrocatalytic N2 Reduction to NH3 Using Enzyme Nitrogenase

07/24/2019

Lance C. Seefeldt, Artavazd Badalyan, Zhi-Yong Yang. The reduction of dinitrogen (N2) to ammonia (NH3) is an important reaction that supports all of life and many industrial processes. An enzyme found in bacteria called nitrogenase catalyzes this reacti

Fabrication of Anisotropic Silver Nanoplatelets on the Surface of TiO2 Fibers for Enhanced Photocatalysis of a Chemical Warfare Agent Simulant, Methyl Paraoxon

Fabrication of Anisotropic Silver Nanoplatelets on the Surface of TiO2 Fibers for Enhanced Photocatalysis of a Chemical Warfare Agent Simulant, Methyl Paraoxon

07/23/2019

Yi Rao, Yuqin Qian. Among the world’s most deadly toxins are a class of organophosphates that are used as chemical warfare agents (CWAs). It is imperative to continue to develop novel means for mitigation and protection against these chemical threats.

Highly active nanostructured CoS2/CoS heterojunction electrocatalysts for aqueous polysulfide/iodide redox flow batteries

Highly active nanostructured CoS2/CoS heterojunction electrocatalysts for aqueous polysulfide/iodide redox flow batteries

07/19/2019

T. Leo Liu, Bo Hu, Wenda Wu. Aqueous polysulfide/iodide redox flow batteries are attractive for scalable energy storage due to their high energy density and low cost. However, their energy efficiency and power density are usually limited by poor electro

Modified substrate specificity of a methyltransferase domain by protein insertion into an adenylation domain of the bassianolide synthetase

Modified substrate specificity of a methyltransferase domain by protein insertion into an adenylation domain of the bassianolide synthetase

07/17/2019

Joan M. Hevel Background: Creating designer molecules using a combination of select domains from polyketide synthases and/ or nonribosomal peptide synthetases (NRPS) continues to be a synthetic goal. However, an incomplete understanding of how protein-pro...

Comparison of halogen with proton transfer. Symmetric and asymmetric systems

Comparison of halogen with proton transfer. Symmetric and asymmetric systems

07/09/2019

Steve Scheiner. Jia Lu. The transfer of the halogen atom X within (A..X..A)+ systems was calculated for A=NH3, OH2, and CH3, and where X=Cl, Br, and I. These potentials are similar to those computed for equivalent proton transfers. Each contains a single...

Mo-, V-, and Fe-Nitrogenases Use a Universal Eight-Electron Reductive-Elimination Mechanism To Achieve N2 Reduction

Mo-, V-, and Fe-Nitrogenases Use a Universal Eight-Electron Reductive-Elimination Mechanism To Achieve N2 Reduction

07/08/2019

Lance C. Seefeldt, Derek F. Harris, Hayden Kallas, Zhi-Yong Yang. Three genetically distinct, but structurally similar, isozymes of nitrogenase catalyze biological N2 reduction to 2NH3: Mo-, V-, and Fe-nitrogenase, named respectively for the metal (M) i

The ability of a tetrel bond to transition a neutral amino acid into a zwitterion

The ability of a tetrel bond to transition a neutral amino acid into a zwitterion

07/04/2019

Steve Scheiner. The interaction between glycine and F2CO/F2SiO occurs through the formation of a π-tetrel bond between the C/Si atom and a carboxyl O atom. The interaction energy is some 20 kJ/mol for the C⋯O tetrel bond, but exceeds 300 kJ/mol for Si⋯

Interfaces of Gas-Aerosol Particles: Relative Humidity and Salt Concentration Effects

Interfaces of Gas-Aerosol Particles: Relative Humidity and Salt Concentration Effects

06/28/2019

Yi Rao, Yuqin Qian, Gang-hua Deng, Jordan Lapp. The growth of aerosol particles is intimately related to chemical reactions in the gas phase and particle phase and at gas−aerosol particle interfaces. While chemical reactions in gas and particle phases a

Structural basis of Type IV CRISPR RNA biogenesis by a Cas6 encoribonuclease

Structural basis of Type IV CRISPR RNA biogenesis by a Cas6 encoribonuclease

06/28/2019

Ryan N. Jackson, Hannah N. Taylor, Valerie M. Crowley, Keith J. Olsen Prokaryotic CRISPR-Cas adaptive immune systems rely on small non-coding RNAs derived from CRISPR loci to recognize and destroy complementary nucleic acids. However, the mechanism of T

Towards Sustainable Environmental Quality: Priority Research Questions for the Australasian Region of Oceania

Towards Sustainable Environmental Quality: Priority Research Questions for the Australasian Region of Oceania

06/24/2019

Kimberly Hageman. Environmental challenges persist across the world, including the Australasian region of Oceania, where biodiversity hotspots and unique ecosystems such as the Great Barrier Reef are common. These systems are routinely affected by mult

High-Resolution ENDOR Spectroscopy Combined with Quantum Chemical Calculations Reveals the Structure of Nitrogenase Janus

High-Resolution ENDOR Spectroscopy Combined with Quantum Chemical Calculations Reveals the Structure of Nitrogenase Janus

06/21/2019

Lance C. Seefeldt. We have shown that the key state in N2 reduction to two NH3 molecules by the enzyme nitrogenase is E4(4H), the “Janus” intermediate, which has accumulated four [e−/H+] and is poised to undergo reductive elimination of H2 coupled to N2

Interfacial Sites between Cobalt Nitride an Cobalt Act as Bifunctional Catalysts for Hydrogen Electrochemistry

Interfacial Sites between Cobalt Nitride an Cobalt Act as Bifunctional Catalysts for Hydrogen Electrochemistry

06/12/2019

Yi Rao, Yujie Sun, Fuzhan Song. Hydrogen (H2) electrochemistry primarily consists of two reactions: hydrogen evolution reaction in water for H2 production (HER) and hydrogen oxidation reaction in hydrogen fuel cells for H2 utilization (HOR). The realiz

Record Low Ionization Potentials of Alkali Metal Complexes with Crown Ethers and Cryptands

Record Low Ionization Potentials of Alkali Metal Complexes with Crown Ethers and Cryptands

06/11/2019

Alexander I. Boldyrev, Nikolay V. Tkachenko. Electronic properties of series of alkali metals complexes with crown ethers and cryptands were studied via DFT hybrid functionals. For [M([2.2.2]crypt)] (M=Li, Na, K) extremely low (1.70–1.52 eV) adiabatic i

Computational Insights into Mg-Cl Complex Electrolytes for Rechargeable Magnesium Batteries

Computational Insights into Mg-Cl Complex Electrolytes for Rechargeable Magnesium Batteries

06/05/2019

T. Leo Liu, Steve Scheiner, Jared B. Moss, Liping Zhang, Kevin V. Nielson, Yujing Bi. DFT calculations were conducted to provide unprecedented thermodynamic insights on tetrahydrofuran (THF) solvation, isomerization, and complexation of possible Mg􀀀 Cl

Forty years of progress in the study of the hydrogen bond

Forty years of progress in the study of the hydrogen bond

06/03/2019

Steve Scheiner. The author looks back at developments over the last few decades concerning the H–bond. The list of atoms involved as proton donor and acceptor has broadened dramatically, including most electronegative atoms and even metals. The factors

Interfacial amino acide support Spa47 oligomerization and <i>shigella</i> type three secretion system activation

Interfacial amino acide support Spa47 oligomerization and shigella type three secretion system activation

05/30/2019

Nicholas E. Dickenson, Sean J. Johnson, Hannah J. Demler, Heather B. Case, Yalemi Morales, Abram R. Bernard. Like many Gram-negative pathogens, Shigella rely on a type three secretion system (T3SS) for injection of effector proteins directly into euka

Comparison between Hydrogen and Halogen Bonds in Complexes of 6-OX-Fulvene with Pnicogen and Chalcogen Electron Donors

Comparison between Hydrogen and Halogen Bonds in Complexes of 6-OX-Fulvene with Pnicogen and Chalcogen Electron Donors

05/29/2019

Steve Scheiner. Quantum chemical calculations are applied to complexes of 6- OX-fulvene (X=H, Cl, Br, I) with ZH3/H2Y (Z=N, P, As, Sb; Y=O, S, Se, Te) to study the competition between the hydrogen bond and the halogen bond. The H-bond weakens as the ba

Probing the structures and bonding of size-selected boron and doped-boron clusters

Probing the structures and bonding of size-selected boron and doped-boron clusters

05/23/2019

Alexander I. Boldyrev. Because of their interesting structures and bonding and potentials as motifs for new nanomaterials, size-selected boron clusters have received tremendous interest in recent years. In particular, boron cluster anions (Bn−) have

Antifungal Activities of 4",6"-Disubstituted Amphiphilic Kanamycins

Antifungal Activities of 4",6"-Disubstituted Amphiphilic Kanamycins

05/16/2019

Cheng-Wei T. Chang, Yagya P. Subedi, Madher N. Alfindee Amphiphilic kanamycins derived from the classic antibiotic kanamycin have attracted interest due to their novel bioactivities beyond inhibition of bacteria. In this study, the recently described 4

Structure and Bonding in [Sb@In8Sb12]3- and [Sb@In8Sb12]5-

Structure and Bonding in [Sb@In8Sb12]3- and [Sb@In8Sb12]5-

05/15/2019

Alexander I. Boldyrev, Nikolay V. Tkachenko, Ivan A. Popov, Nikita Fedik.

On the ability of pnicogen atoms to engage in both σ and π-hole complexes. Heterodimers of ZF2C6H5 (Z = P, As, Sb, Bi) and NH3

On the ability of pnicogen atoms to engage in both σ and π-hole complexes. Heterodimers of ZF2C6H5 (Z = P, As, Sb, Bi) and NH3

05/08/2019

Steve Scheiner. When bound to a pair of F atoms and a phenyl ring, a pyramidal pnicogen (Z) atom can form a pnicogen bond wherein an NH3 base lies opposite one F atom. In addition to this σ-hole complex, the ZF2C6H5 molecule can distort in such a way th

Structures of clusters surrounding ions stabilized by hydrogen, halogen, chalcogen, and pnicogen bonds

Structures of clusters surrounding ions stabilized by hydrogen, halogen, chalcogen, and pnicogen bonds

05/05/2019

Steve Scheiner. Four H-binding HCl and HF molecules position themselves at the vertices of a tetrahedron when surrounding a central Cl−. Halogen bonding BrF and ClF form a slightly distorted tetrahedron, a tendency that is amplified for ClCN which fo

Natural Bioactive Compounds

Natural Bioactive Compounds

05/02/2019

Cheng-Wei Tom Chang Nature has long provided us with molecules for therapeutic applications limited only by the imagination and creativity of mankind. Ancient civilizations such as those that once existed in China, Greece, India and Egypt left numerous ex...

Influence of monomer deformation on the competition between two types of r-holes in tetrel bonds

Influence of monomer deformation on the competition between two types of r-holes in tetrel bonds

04/30/2019

Steve Scheiner. One of several tetrel (T) atoms was covalently attached to three F atoms and a substituted phenyl ring. A NH3 base can form a tetrel bond with TF3C6H2R3 (T = Si, Ge, Sn, Pb; R = H, F, CH3) in a position opposite either an F atom or the r

Examining Product Specificity in Protein Arginine Methyltransferase 7 (PRMT7) Using Quantum and Molecular Mechanical Simulations

Examining Product Specificity in Protein Arginine Methyltransferase 7 (PRMT7) Using Quantum and Molecular Mechanical Simulations

04/29/2019

Joan M. Hevel Protein arginine methyltransferase 7 (PRMT7) catalyzes the formation of monomethylarginine (MMA) but is incapable of performing a dimethylation. Given that PRMT7 performs vital functions in mammalian cells and has been implicated in a variet...

Multiple local o-aromaticity of nonagermanide clusters

Multiple local o-aromaticity of nonagermanide clusters

04/25/2019

Alexander I. Boldyrev, Nikolay V. Tkachenko. Nonagermanide clusters are widely used in inorganic synthesis and are actively studied by experimentalists and theoreticians. However, chemical bonding of such versatile species is still not completely unde

Interactions of (MY)6 (M = Zn, Cd; Y = O, S, Se) quantum dots with N-bases

Interactions of (MY)6 (M = Zn, Cd; Y = O, S, Se) quantum dots with N-bases

04/25/2019

Steve Scheiner. (MY)6 clusters, with M = Zn and Cd and Y = O, S, Se, form double-layer drum-like structures containing M–Y covalent bonds. The positive regions near the M atoms attract the N atom of both NH3 and NMe3 so as to form a noncovalent M···N b

High-Resolution Photoelectron Imaging of IrB3-: Observation of a pi-Aromatic B3+ Ring Coordinated to a Transition Metal

High-Resolution Photoelectron Imaging of IrB3-: Observation of a pi-Aromatic B3+ Ring Coordinated to a Transition Metal

04/25/2019

Alexander I. Boldyrev, Maksim Kulichenko. Abstract: In a high-resolution photoelectron imaging and theoretical study of the IrB3 @ cluster, two isomers were observed experimentally with electron affinities (EAs) of 1.3147(8) and 1.937(4) eV. Quantum cal

Hydrated Sulfate Clusters SO4^2-(H2O)n (n = 1-40): Charge Distribution Through Solvation Shells and Stabilization

Hydrated Sulfate Clusters SO4^2-(H2O)n (n = 1-40): Charge Distribution Through Solvation Shells and Stabilization

04/17/2019

Alexander I. Boldyrev, Maksim Kulichenko, Nikita Fedik. Investigations of inorganic anion SO4 2− interactions with water are crucial for understanding the chemistry of its aqueous solutions. It is known that the isolated SO4 2− dianion is unstable, and

On the capability of metal-halogen groups to participate in halogen bonds

On the capability of metal-halogen groups to participate in halogen bonds

04/17/2019

Steve Scheiner. A number of halogen (X) atoms were covalently attached to a metal (M) and the ability of the X atom to act as electron acceptor in a halogen bond to nucleophile NCH was assessed. Both Cl and Br were considered as halogen atom, with NH3 a

Chemical bonding analysis of excited states using the adaptive natural density partitioning method

Chemical bonding analysis of excited states using the adaptive natural density partitioning method

04/17/2019

Alexander I. Boldyrev, Nikolay Tkachenko. A novel approach to chemical bond analysis for excited states has been developed. Using an extended adaptive natural density partitioning method (AdNDP) as implemented in AdNDP 2.0 code, we obtained chemicall

Electrochemical Dinitrogen Reduction to Ammonia by Mo2N: Catalysis or Decomposition?

Electrochemical Dinitrogen Reduction to Ammonia by Mo2N: Catalysis or Decomposition?

04/10/2019

Lance C. Seefeldt, T. Leo Liu, Maowei Hu, Bo Hu. Instead of catalyzing electrochemical reduction of N2, we found that tetragonal Mo2N undergoes decomposition and results in the generation of ammonia. The present results call urgent attention to the need

Molecular Dynamics Study of a New Metastable Allotropic Crystalline Form of Gallium - Supertetrahedral Gallium

Molecular Dynamics Study of a New Metastable Allotropic Crystalline Form of Gallium - Supertetrahedral Gallium

04/08/2019

Alexander I. Boldyrev. A new metastable crystalline form of gallium has been computationally designed using density functional calculations with imposing periodic boundary conditions. The geometric and electronic structures of the predicted new allotrop

3-Hydroxyflavones and 3-Hydroxy-4-oxoquinolines as Carbon Monoxide-Releasing Molecules

3-Hydroxyflavones and 3-Hydroxy-4-oxoquinolines as Carbon Monoxide-Releasing Molecules

03/30/2019

Lisa M. Berreau, Tatiana Soboleva Carbon monoxide-releasing molecules (CORMs) that enable the delivery of controlled amounts of CO are of strong current interest for applications in biological systems. In this review, we examine the various conditio

Optical Stability of 1,1'-Binaphthyl Derivatives

Optical Stability of 1,1'-Binaphthyl Derivatives

03/29/2019

Steve Scheiner. Nikolay V. Tkachenko. The racemization process of various 1,1′-binaphthyl derivatives is studied by quantum calculations. The preferred racemization pathway passes through a transition state belonging to the Ci symmetry group. The ene

A Stable, Non-Corrosive Perfluorinated Pinacolatoborate Mg Electrolyte for Rechargeable Mg Batteries

A Stable, Non-Corrosive Perfluorinated Pinacolatoborate Mg Electrolyte for Rechargeable Mg Batteries

03/22/2019

Tianbiao Leo Liu, Jian Luo, Yujing Bi, Liping Zhang, Xiaoyin Zhang. Mg batteries are a promising energy storage system because of the physicochemical merits of Mg as an anode material. However, the lack of electrochemically and chemically stable Mg e

Evaluation of attractive interactions in the second coordination sphere of iron complexes containing pendant amines

Evaluation of attractive interactions in the second coordination sphere of iron complexes containing pendant amines

03/15/2019

Tianbiao Liu. The interactions between pendant amines in the second coordination sphere and ligands in the first coordination sphere are important for understanding the structures and reactivity of complexes containing PR2NR′2 ligands, which have been s

Inorganic Molecular Electride Mg4O3: Structure, Bonding, and Nonlinear Optical Properties

Inorganic Molecular Electride Mg4O3: Structure, Bonding, and Nonlinear Optical Properties

03/14/2019

Alexander I. Boldyrev, Maksim Kulichenko, Nikita Fedik. Growing demands of material science and, in particular, in the field of nonlinear optics (NLO) encourage us to look for stable highly polarizable molecules with excess diffuse electrons. An unusua

Air Analysis  l  Sampling

Air Analysis l Sampling

03/12/2019

Kimberly J. Hageman, Ashlie D. Kinross. The composition of air has been a topic of interest since the early days of scientific inquiry. In modern times, the need has arisen to characterize and quantify a variety of harmful substances that are present i

A 1.51 V pH neutral redox flow battery towards scalable energy storage

A 1.51 V pH neutral redox flow battery towards scalable energy storage

03/12/2019

T. Leo Liu, Jian Luo, Wenda Wu, Camden Debruler, Bo Hu, Maowei Hu. Aqueous redox flow batteries using low-cost organic and inorganic active materials have received growing interest for sustainable energy storage. In this study, a low-cost, high redox po

Molecular rotation in 3 dimensions at an air/water interface using femtosecond time resolved sum frequency generation

Molecular rotation in 3 dimensions at an air/water interface using femtosecond time resolved sum frequency generation

03/07/2019

Yi Rao, Yuqin Qian, Gang-Hua Deng, Ashlie Kinross. This paper presents the first study of the rotations of rigid molecules in 3 dimensions at the air/water interface, using the femtosecond time resolved sum frequency generation (SFG) technique. For the

The NifZ accessory protein has an equivalent function in maturation of both nitrogenase MoFe protein P-clusters

The NifZ accessory protein has an equivalent function in maturation of both nitrogenase MoFe protein P-clusters

03/01/2019

Lance C. Seefeldt, Zhi-Yong Yang. The Mo-dependent nitrogenase comprises two interacting components called the Fe protein and the MoFe protein. The MoFe protein is an a2b2 heterotetramer that harbors two types of complex metalloclusters, both of which a

Transition State Analysis of the Reaction Catalyzed by the Phosphotriesterase from <i>Sphingobium</i> sp. TCM1

Transition State Analysis of the Reaction Catalyzed by the Phosphotriesterase from Sphingobium sp. TCM1

02/27/2019

Alvan C. Hengge Organophosphorus flame retardants are stable toxic compounds used in nearly all durable plastic products and are considered major emerging pollutants. The phosphotriesterase from Sphingobium sp. TCM1 (Sb-PTE) is one of the few enzymes know...

Structural and Functional Characterization of Sulfonium Carbon-Oxygen Hydrogen Bonding in the Deoxyamino Sugar Methyltransferase TylM1

Structural and Functional Characterization of Sulfonium Carbon-Oxygen Hydrogen Bonding in the Deoxyamino Sugar Methyltransferase TylM1

02/27/2019

Steve Scheiner. The N-methyltransferase TylM1 from Streptomyces fradiae catalyzes the final step in the biosynthesis of the deoxyamino sugar mycaminose, a substituent of the antibiotic tylosin. The high-resolution crystal structure of TylM1 bound to th

Heme-Derived Bilins

Heme-Derived Bilins

02/27/2019

Cheng-Wei T. Chang Living things on Earth depend on heme – the iron‐cyclic tetrapyrrole complex that harnesses iron's oxidizing powers. Heme is toxic, but Nature has evolved ways to control it. One way is breaking it with heme oxygenase which lowers its l...

Two names of stability: Spherical aromatic or superatomic intermetalloid cluster [Pd3Sn8Bi6]4-

Two names of stability: Spherical aromatic or superatomic intermetalloid cluster [Pd3Sn8Bi6]4-

02/22/2019

Alexander I. Boldyrev, Nikita Fedik, Maksim Kulichenko. Amidst the general bonding patterns designed to explain stability aromaticity has leading role. Going far away beyond classic notion of organic chemistry aromaticity was proven to be a useful to

Facile fabrication of periodic arrays of vertical Si nanoholes on (001)Si substrate with broadband light absorption properties

Facile fabrication of periodic arrays of vertical Si nanoholes on (001)Si substrate with broadband light absorption properties

02/22/2019

C.W. Chang This study presents a facile and straightforward approach to fabricating periodic arrays of Au nanodisks and vertically aligned, depth- and morphology-controllable Si nanoholes on (001)Si substrates by combining self-assembled nanosphere

Inhibition of Connexion Hemichannels by New Aminoglycosids without Antibiotic Activity

Inhibition of Connexion Hemichannels by New Aminoglycosids without Antibiotic Activity

02/15/2019

Cheng-Wei T. Chang, Yagya P. Subedi, Madher N. Alfindee

Hexacoordinated Tetrel-Bonded Complexes between TF4 (T=Si, Ge, Sn, Pb) and NCH: Competition between σ- and π-Holes

Hexacoordinated Tetrel-Bonded Complexes between TF4 (T=Si, Ge, Sn, Pb) and NCH: Competition between σ- and π-Holes

02/15/2019

Steve Scheiner. In order to accommodate the approach of two NCH bases, a tetrahedral TF4 molecule (T=Si, Ge, Sn, Pb) distorts into an octahedral structure in which the two bases can be situated either cis or trans to one another. The square planar geom

Tracking CO Release in Cells via the Luminescence of Donor Molecules and/or their By-Products

Tracking CO Release in Cells via the Luminescence of Donor Molecules and/or their By-Products

02/11/2019

Lisa M. Berreau, Tatiana Soboleva Carbon monoxide (CO) is a bioactive signalling molecule that is produced endogenously via the breakdown of heme. Beneficial health effects associated with the delivery of CO gas have spurred the development of CO‐relea

Transition-State Interactions in a Promiscuous Enzyme: Sulfate and Phosphate Monoester Hydrolysis by <i>Pseudomonas aeruginosa</i> Arylsulfatase

Transition-State Interactions in a Promiscuous Enzyme: Sulfate and Phosphate Monoester Hydrolysis by Pseudomonas aeruginosa Arylsulfatase

02/07/2019

Alvan C. Hengge Pseudomonas aeruginosa arylsulfatase (PAS) hydrolyzes sulfate and, promiscuously, phosphate monoesters. Enzyme-catalyzed sulfate transfer is crucial to a wide variety of biological processes, but detailed studies of the mechanistic contrib...

Carboxylic Anchoring Dye p-Ethyl Red Does Not Adsorb Directly onto TiO2 Particles in Protic Solvents

Carboxylic Anchoring Dye p-Ethyl Red Does Not Adsorb Directly onto TiO2 Particles in Protic Solvents

02/06/2019

Yi Rao. Adsorption of the carboxylic anchoring dye, pethyl red (p-ER), onto TiO2 nanoparticles in protic vs aprotic solvents was studied in situ using the surface-specific technique, second harmonic light scattering (SHS). Two different adsorption sch

Switchable Aromaticity in an Isostructural Mn Phthalocyanine Series Isolated in Five Separate Redox States

Switchable Aromaticity in an Isostructural Mn Phthalocyanine Series Isolated in Five Separate Redox States

02/04/2019

Steve Scheiner. The synthesis and characterization of a new phthalocyanine (Pc) Mn-nitride complex, (OEtPc)MnN (2; OEtPc = 1,4,8,11,15,18,22,25-octaethoxy-Pc), as well as its stable, readily accessible oxidized (2+ and 22+) and reduced (2–, 22–) congen

Comparison of σ-hole and π-hole tetrel bonds in complexes of borazine with TH3F and F2TO/H2TO (T = C, Si, Ge)

Comparison of σ-hole and π-hole tetrel bonds in complexes of borazine with TH3F and F2TO/H2TO (T = C, Si, Ge)

01/25/2019

Steve Scheiner. The complexes between borazine and TH3F/F2TO/H2TO (T = C, Si, Ge) are investigated with high‐level quantum chemical calculations. Borazine has three sites of negative electrostatic potential: the N atom, the ring center, and the H atom

Catalytic mechanism for the conversion of salicylate into catechol by the flavin-dependent monooxygenase salicylate hydroxylase

Catalytic mechanism for the conversion of salicylate into catechol by the flavin-dependent monooxygenase salicylate hydroxylase

01/24/2019

Alvan C. Hengge Salicylate hydroxylase (NahG) is a flavin-dependent monooxygenase that catalyzes the decarboxylative hydroxylation of salicylate into catechol in the naphthalene degradation pathway in Pseudomonas putida G7.We explored the mechanism of act...

Development of Fungal Selective Amphiphilic Kanamycin: Cost-Effective Synthesis and Use of Fluorescent Analogs for Mode of Action Investigation

Development of Fungal Selective Amphiphilic Kanamycin: Cost-Effective Synthesis and Use of Fluorescent Analogs for Mode of Action Investigation

01/23/2019

Cheng-Wei Tom Chang, Yagya Prasad Subedi Amphiphilic aminoglycosides have attracted interest due to their novel antifungal activities. A crucial but often neglected factor for drug development in academia is cost of production. Herein is reported a one-st...

Dual Geometry Schemes in Tetrel Bonds: Complexes between TF4 (T=Si, Ge, Sn) and Pyridine Derivatives

Dual Geometry Schemes in Tetrel Bonds: Complexes between TF4 (T=Si, Ge, Sn) and Pyridine Derivatives

01/21/2019

Steve Scheiner. When an N-base approaches the tetrel atom of TF4 (T = Si, Ge, Sn) the latter molecule deforms from a tetrahedral structure in the monomer to a trigonal bipyramid. The base can situate itself at either an axial or equatorial position, le

Unprecedented Capacity and Stability of Ammonium Ferrocyanide Catholyte in pH Neutral Aqueous Redox Flow Batteries

Unprecedented Capacity and Stability of Ammonium Ferrocyanide Catholyte in pH Neutral Aqueous Redox Flow Batteries

01/16/2019

T. Leo Liu, Jian Luo, Bo Hu, Camden Debruler, Yujing Bi, Maowei Hu, Wenda Wu. Aqueous organic/organometallic redox flow batteries (AORFBs) have gained increasing attention for large-scale storage of intermittent renewable energy (e.g., solar and wind) d

Development of ultrafast broadband electronic sum frequency generation for charge dynamics at surfaces and interfaces

Development of ultrafast broadband electronic sum frequency generation for charge dynamics at surfaces and interfaces

01/14/2019

Yi Rao, Gang-Hua Deng, Yuqin Qian. Understandings of population and relaxation of charges at surfaces and interfaces are essential to improve charge collection efficiency for energy conversion, catalysis, and photosynthesis. Existing time-resolved surf

Structure and bonding of new borong and carbon superpolyhedra

Structure and bonding of new borong and carbon superpolyhedra

01/10/2019

Alexander I. Boldyrev, Nikita S. Fedik. Using the DFT methods, we computationally predict the stability of cage compounds E4nRn (E = B, C; R = H, F; n = 4, 8, 12, 24) based on Platonic bodies and Archimedean polyhedrons in which all vertices are replace

Differential Binding of Tetrel-Bonding Bipodal Receptors to Monatomic and Polyatomic Anions

Differential Binding of Tetrel-Bonding Bipodal Receptors to Monatomic and Polyatomic Anions

01/09/2019

Steve Scheiner. Previous work has demonstrated that a bidentate receptor containing a pair of Sn atoms can engage in very strong interactions with halide ions via tetrel bonds. The question that is addressed here concerns the possibility that a recepto

The ammonium transporter AmtB and the PII signal transduction protein GlnZ are required to inhibit DraG in <i>Azospirillum brasilense</i>

The ammonium transporter AmtB and the PII signal transduction protein GlnZ are required to inhibit DraG in Azospirillum brasilense

01/09/2019

Lance C. Seefeldt. The ammonium-dependent posttranslational regulation of nitrogenase activity in Azospirillum brasilense requires dinitrogenase reductase ADPribosyl transferase (DraT) and dinitrogenase reductase ADP-glycohydrolase (DraG). These enzymes

A Voltammetric Study of Nitrogenase Catalysis Using Electron Transfer Mediators

A Voltammetric Study of Nitrogenase Catalysis Using Electron Transfer Mediators

01/04/2019

Lance C. Seefeldt, Artavazd Badalyan, Zhi-Yong Yang. Nitrogenase catalyzes the reduction of an array of small molecules, including N2 to NH3, by delivering electrons and protons to substrates bound to the active site metal cluster FeMocofactor. A chall

Methods in ENZYMOLOGY: Application of affinity purification methods for analysis of the nitrogenase system from <i>Azotobacter vinelandii</i>

Methods in ENZYMOLOGY: Application of affinity purification methods for analysis of the nitrogenase system from Azotobacter vinelandii

12/31/2018

Lance C. Seefeldt, Zhi-Yong Yang. Pg. 231-251. Nitrogenases are complex two-component metalloenzymes that catalyze biological nitrogen fixation. Three different nitrogenase types are found in the model nitrogen-fixing microbe azotabacter vinelandii. In

Computationally Designed Crystal Structures of the Supertetrahedral Al4X (X=B,C,Al,Si) Solids

Computationally Designed Crystal Structures of the Supertetrahedral Al4X (X=B,C,Al,Si) Solids

12/14/2018

Alexander I. Boldyrev. New metastable crystalline forms of the supertetrahedral Al4X (X = B, C, Al, Si) solids have been computationally designed using density functional theory calculations with imposing of periodic boundary conditions. The geometric

Cationic Anthrquinone Analogs as Selective Antimicrobials

Cationic Anthrquinone Analogs as Selective Antimicrobials

12/10/2018

Cheng-Wei Tom Chang, Yagya Prasad Subedi Development of new antibiotics is always needed in the fight against growing threat from multiple drug–resistant bacteria, such as resistant Gram-negative (G−) Escherichia coli and Klebsiella pneumoniae. While

Difluorophophorane-Flattened Phosphorene through Difluorination

Difluorophophorane-Flattened Phosphorene through Difluorination

11/27/2018

Alexander I. Boldyrev. We computationally showed that by difluorination of phosphorene we can make a new material difluorphosphorane (DFP) with perfectly planar honeycomb structure out of phosphorus atoms with fluorine atoms attached to every phosphorus

Shutting down shigella secretions: characterizing small molecule type three secretion system ATPase inhibitors

Shutting down shigella secretions: characterizing small molecule type three secretion system ATPase inhibitors

11/21/2018

Heather B. Case, Dominic S. Mattock and Nicholas E. Dickenson Many important human pathogens rely on one or more type three secretion systems (T3SSs) to inject bacterial effector proteins directly into the host cell cytoplasm. Secretion of protein through...

Crystallographic and Computational Characterization of Methyl Tetrel Bonding in S-Adenosylmethionine-Dependent Methyltransferases

Crystallographic and Computational Characterization of Methyl Tetrel Bonding in S-Adenosylmethionine-Dependent Methyltransferases

11/13/2018

Steve Scheiner. Tetrel bonds represent a category of non-bonding interaction wherein an electronegative atom donates a lone pair of electrons into the sigma antibonding orbital of an atom in the carbon group of the periodic table. Prior computational s

Tandem Solar FLow Batteries for Conversion, Storage, and Utilization of Solar Energy

Tandem Solar FLow Batteries for Conversion, Storage, and Utilization of Solar Energy

11/08/2018

T. Leo Liu, Jian Luo. In this issue of Chem, Jin and coworkers present the design principles and demonstration of a highly efficient integrated solar flow battery (SFB) device that can be configured to perform all the requisite functions from solar ener

Kinetic characterization of the shigella type three secretions system ATPase spa47 using ATP
Carbene triel bonds between TrR3 (Tr = B, Al) and N-heterocyclic carbenes

Carbene triel bonds between TrR3 (Tr = B, Al) and N-heterocyclic carbenes

11/02/2018

Steve Scheiner. The carbene triel bond is predicted and characterized by theoretical calculations. The C lone pair of N‐heterocyclic carbenes (NHCs) is allowed to interact with the central triel atom of TrR3 (Tr = B and Al; R = H, F, Cl, and Br). The en

Control of electron transfer in nitrogenase

Control of electron transfer in nitrogenase

09/08/2018

Lance C. Seefeldt. The bacterial enzyme nitrogenase achieves the reduction of dinitrogen (N2) to ammonia (NH3) utilizing electrons, protons, and energy from the hydrolysis of ATP. Building on earlier foundational knowledge, recent studies provide molec

Tuning the biological activity of cationic anthraquinone analogues specifically toward staphylococcus aureus

Tuning the biological activity of cationic anthraquinone analogues specifically toward staphylococcus aureus

08/18/2018

Yagya Prasad Subedi, madher N. Alfindee, Jaya P. Shestha, and Cheng-Wei Tom Chang Abstract: Development of new antibacterial agents against drug resistant bacteria is an imminent task, especially against methicillin-resistant Staphylococcus aureus (MRSA)....

A yoph ptp1b chimera shows the importance of the wpd-loop sequence to the activity, structure, and dynamics of protein tyrosine phosphatases

A yoph ptp1b chimera shows the importance of the wpd-loop sequence to the activity, structure, and dynamics of protein tyrosine phosphatases

08/15/2018

Gwendolyn Moise, Yalemi Morales, Victor Beaumont, Timothy Caradonna, J. Patrick Loria, Sean J. Johnson, and Alvan C. Hengge ABSTRACT: To study factors that affect WPD-loop motion in protein tyrosine phosphatases (PTPs), a chimera of PTP1B and YopH was cre...

In situ chemical analysis of the gas-aerosol particle interface

In situ chemical analysis of the gas-aerosol particle interface

08/15/2018

Yuqin Qian, Gang-hua Deng, and Yi Rao The gas–aerosol particle interface is believed to contribute to the growth of secondary organic aerosols in the atmosphere. Despite its importance, the chemical composition of the interface has not been probed directl...

Synthesis and biological activity investigation of azole and quinone hybridized phosphonates

Synthesis and biological activity investigation of azole and quinone hybridized phosphonates

08/01/2018

Yagya Prasad Subedi, Madher N. Alfindee, Jaya P. Shrestha, Greg Becker, Michelle Grilley, Jon Y. Takemoto, Cheng-Wei Tom Chang ABSTRACT: Phosphonates, azoles and quinones are pharmacophores found in bioactive compounds. A series of phosphonates conjugated...

A new era for electron bifurcation

A new era for electron bifurcation

08/01/2018

Lance C. Seefeldt. Electron bifurcation, or the coupling of exergonic and endergonic oxidation-reduction reactions, was discovered by Peter Mitchell and provides an elegant mechanism to rationali

Visible-light-activated quinolone carbone-monoxide-releasing molecule: prodrug and albumin-assisted delivery enables anticancer and potent anti-inflammatory effects

Visible-light-activated quinolone carbone-monoxide-releasing molecule: prodrug and albumin-assisted delivery enables anticancer and potent anti-inflammatory effects

07/09/2018

Marina Popova, Tatiana Soboleva, Suliman Ayad, Abby D. Benninghoff, and Lisa M. Berreau Abstract: The delivery of controlled amounts of carbon monoxide (CO) to biological targets is of significant current interest. Very few CO-releasing compounds are curr...

Mitochndrial-localized versus cytosolic Intracellular CO-releasing organic photoCORMs: evaluation of CO effect using bioenergetics

Mitochndrial-localized versus cytosolic Intracellular CO-releasing organic photoCORMs: evaluation of CO effect using bioenergetics

06/22/2018

Tatiana Soboleva, Hector J. Esquer, Stacey N. Anderson, Lisa M. Berreau, and Abby D. Benninghoff ABSTRACT: While interactions between carbon monoxide (CO) and mitochondria have been previously studied, the methods used to deliver CO (gas or CO-releasing m...

Inhibition of connexin hemichannels by new amphiphilic aminoglycosides without antibiotic activity

Inhibition of connexin hemichannels by new amphiphilic aminoglycosides without antibiotic activity

06/19/2018

Madher N. Alfindee, Yagya P. Subedi, Mariana C. Fiori, Srinivasan Krishnan, Abbey Kjellgren, Guillermo A. Altenberg, and Cheng-Wei T. Chang ABSTRACT: Connexins hemichannels (HCs) from adjacent cells form gap junctional channels that mediate cell-to-cell c...

Multicenter bonding effects in oxygen vacancy in the bulk an don the surface of MgO

Multicenter bonding effects in oxygen vacancy in the bulk an don the surface of MgO

05/10/2018

Ivan A. Popov, Elisa Jimenez-Izal, Anatassia N. Alexandrova and Alexander I. Boldyrev ABSTRACT: We have studied the electronic structure of F-centers in the bulk and on the (100) surface of the MgO crystal. Chemical bonding analysis was performed using t...

Structure of frequency-interacting RNA helicase from neurospora crassa reveals high flexibility in a domain critical for circadian rhythm and RNA surveiillance

Structure of frequency-interacting RNA helicase from neurospora crassa reveals high flexibility in a domain critical for circadian rhythm and RNA surveiillance

05/02/2018

Morales Y., Olsen KJ, Bulcher JM, Johnson SJ ABSTRACT:The FRH (frequency-interacting RNA helicase) protein is the Neurospora crassa homolog of yeast Mtr4, an essential RNA helicase that plays a central role in RNA metabolism as an activator of the nucle

Antifungal amphiphilic kanamycins: new life for an old drug

Antifungal amphiphilic kanamycins: new life for an old drug

04/15/2018

Yagya Prasad Subedi, Madher N. Alfinee, Jon Y. Takemoto and Cheng-Wei Tom Chang Classical aminoglycoside antibiotics are obsolete or hampered by the emergence of drug resistant bacteria. Recent discoveries of antifungal amphiphilic kanamycins offer new

Electrocatalytic CO2 reduction catalyzed by nitrogenase MoFe and FeFe proteins

Electrocatalytic CO2 reduction catalyzed by nitrogenase MoFe and FeFe proteins

04/01/2018

Bo Hu, Derek F. Harris, Dennis R. Dean, T. Leo Liu, Zhi-Yong Yang, Lance C. Seefeldt: Nitrogenases catalyze biological dinitrogen (N2) reduction to ammonia (NH3), and also reduce a number of non-physiological substrates, including carbon dioxide (CO2) to ...

MxiN differentially regulates monomeric and oligomeric species of the Shigella type three secretion system ATPase Spa47

MxiN differentially regulates monomeric and oligomeric species of the Shigella type three secretion system ATPase Spa47

03/29/2018

Heather B. Case and Nicholas E. Dickenson: Shigella rely entirely on the action of a single type three secretion system (T3SS) to support cellular invasion of colonic epithelial cells and to circumvent host immune responses. The ATPase Spa47 resides at th...

Thermodynamic measures of binding strength in pnicogen, chalcogen, halogen, and hydrogen bonds

Thermodynamic measures of binding strength in pnicogen, chalcogen, halogen, and hydrogen bonds

03/20/2018

Jared B. Moss, Upendra Adhikari, and Steve Scheiner: Thermodynamic quantities ΔEelec, ΔH, and ΔG are computed by various different levels of ab initio quantum theory. The values obtained are searched for any reversals in order of stability between differe...

Excitonic and confinement effects of 2D layered (C10H21NH3) 2PbBr4 single crystals

Excitonic and confinement effects of 2D layered (C10H21NH3) 2PbBr4 single crystals

03/20/2018

Huatao Yin, Lei Jin, Yuqin Qian, Xia Li, Yuhao Wu, Michael S. Bowen, Deirdre Kaan, Chao He, Derek I Wozniak, Bolei Xu, Asa J Lewis, Weiwei Shen, Ke Chen, Graham E Dobereiner, Yan Zhao, Bradford B Wayland, Yi Rao Recognition of unusual optoelectronic prop...

Electrolyzer design for flexible decoupled water splitting and organic upgrading with electron reservoirs

Electrolyzer design for flexible decoupled water splitting and organic upgrading with electron reservoirs

03/08/2018

Wei Li, Nan Jiang, Bo Hu, Xuan Liu, Fuzhan Song, Guanqun Han, Taylor J. Jordan, Tanner B. Hanson, T. Leo Liu, Yujie Sun: Conventional water-splitting electrolysis drives the H2 and O2 evolution reactions (HER and OER, respectively) simultaneously with lar...

Two electron utilization of methyl viologen anolyte in nonaqueous organic redox flow battery

Two electron utilization of methyl viologen anolyte in nonaqueous organic redox flow battery

03/02/2018

Methyl viologen (MV) as a bench-mark anolyte material has been frequently applied in aqueous organic redox flow batteries (AORFBs) towards large-scale renewable energy storage. However, only the first reduction of MV was utilized in aqueous electrolytes b...

A sulfonate-functionalized viologen enabling neutral cation exchange, aqueous organic redox flow batteries toward renewable energy storage

A sulfonate-functionalized viologen enabling neutral cation exchange, aqueous organic redox flow batteries toward renewable energy storage

02/13/2018

Camden DeBruler, Bo Hu, Jared Moss, Jian Luo, and T. Leo Liu: Redox flow batteries using synthetically tunable and resource abundant organic molecules have gained increasing attention for large-scale energy storage. Herein we report a sulfonate-functional...

Mechanism of N2 reduction catalyzed by Fe-nitrogenase involves reductive elimination of H2

Mechanism of N2 reduction catalyzed by Fe-nitrogenase involves reductive elimination of H2

02/01/2018

Derek F. Harris, Dmitriy A. Lukoyanov, Sudipta Shaw, Phil Compton, Monika Tokmina-Lukaszewska, Brian Bothner, Neil Kelleher, Dennis R. Dean, Brian M. Hoffman, and Lance C. Seefeldt: Of the three forms of nitrogenase (Mo-nitrogenase, V-nitrogenase, and Fe-...

One-step synthesis of carbohydrate esters as antibacterial and antifungal agents

One-step synthesis of carbohydrate esters as antibacterial and antifungal agents

02/01/2018

Madher N. AlFindee, Qian Zhang, Yagya Prasad Subedi, Jaya P. Shrestha, Yukie Kawasaki, Michelle Grilley, Jon Y. Takemoto, Cheng-Wei Tom Chang: Carbohydrate esters are biodegradable, and the degraded adducts are naturally occurring carbohydrates and fatty ...

Phe71 in type III trypanosoomal protein rrginine methyltransferase 7 (TbPRMT7) restricts to monomethylation

Phe71 in type III trypanosoomal protein rrginine methyltransferase 7 (TbPRMT7) restricts to monomethylation

01/29/2018

Tamar B. Caceres, Abhishek Thakur, Owen M Price, Nicole Ippolito, Jun Li, Jun Qu, Orlando Acevedo and Joan Hevel ABSTRACT: Protein arginine methyltransferase 7 (PRMT7) is unique within the PRMT family as it is the only isoform known to exclusively make m...

Aerogen bonds formed between AeOF2 (Ae = Kr, Xe) and diazines: comparisons between r-hole and p-hole complexes†

Aerogen bonds formed between AeOF2 (Ae = Kr, Xe) and diazines: comparisons between r-hole and p-hole complexes†

01/10/2018

Wiktor Zierkiewicz, Mariusz Michalczyka and Steve Scheiner: The interaction between KrOF2 or XeOF2 and the 1,2, 1,3, and 1,4 diazines is characterized chiefly by a Kr/XeN aerogen bond, as deduced from ab initio calculations. The most stable dimers take ad...

A π-conjugation extended viologen as a two-electron storage anolyte for total organic aqueous redox flow batteries

A π-conjugation extended viologen as a two-electron storage anolyte for total organic aqueous redox flow batteries

01/02/2018

Extending the conjugation of viologen by a planar thiazolo[5,4-d]thiazole (TTz) framework and functionalizing the pyridinium with hydrophilic ammonium groups yielded a highly water-soluble π-conjugation extended viologen, 4,4′-(thiazolo[5,4-d]thiazole-2,5...

Designer two-electron storage viologen anolyte materials for neutral aqueous organic redox flow batteries

Designer two-electron storage viologen anolyte materials for neutral aqueous organic redox flow batteries

12/14/2017

Aqueous organic redox flow batteries (AORFBs) are highly attractive for large-scale energy storage because redox-active organic molecules are synthetically tunable, sustainable, and potentially low cost. Here, we show that rational molecular engineering y...

An H2S-sensing/CO-releasing flavonol that operates via logic gates

An H2S-sensing/CO-releasing flavonol that operates via logic gates

12/13/2017

Tatiana Soboleva, Abby D. Benninghoff, and Lisa M. Berreau: Signaling molecules, including H2S and CO, are involved in a complex interplay within cells to maintain cellular homeostasis. In order to investigate the intracellular interplay of different gaso...

Suppression of wheat Fusarium head blight by novel amphiphilic aminoglycoside fungicide K20

Suppression of wheat Fusarium head blight by novel amphiphilic aminoglycoside fungicide K20

12/01/2017

Jon Y. Takemoto, Stephen N. Wegulo, Gary Y. Yuen, Julie A. Stevens, Charlene C. Jochum, Cheng-Wei T. Chang, Yukie Kawasaki, Gene W. Miller: K20 is a novel amphiphilic aminoglycoside capable of inhibiting many fungal species. K20's capabilities to inhibit ...

Dirac cones in two-dimensional borane

Dirac cones in two-dimensional borane

11/28/2017

Miguel Martinez-Canales, Timur R. Galeev, Alexander I. Boldyrev, and Chris J. Pickard: We introduce two-dimensional borane, a single-layered material of BH stoichiometry, with promising electronic properties. We show that, according to Density Functional ...

Deoxycholate-enhanced shigella virulence Is regulated by a rare π-Helix in the type three secretion system tip protein IpaD

Deoxycholate-enhanced shigella virulence Is regulated by a rare π-Helix in the type three secretion system tip protein IpaD

11/14/2017

Abram R. Bernard, T. Carson Jessop, Prashant Kumar, and Nicholas E. Dickenson: Type three secretion systems (T3SS) are specialized nanomachines that support infection by injecting bacterial proteins directly into host cells. The Shigella T3SS has uniquely...

Conformational dynamics of DNA binding and Cas3 recruitment by the CRISPR RNA-guided cascade complex

Conformational dynamics of DNA binding and Cas3 recruitment by the CRISPR RNA-guided cascade complex

10/16/2017

Paul B. G. van Erp, Angela Patterson, Ravi Kant, Luke Berry, Sarah M. Golden, Brittney L. Forsman, Joshua Carter, Ryan N. Jackson, Brian Bothner, and Blake Wiedenheft: Bacteria and archaea rely on CRISPR (clustered regularly interspaced short palindromic ...

Understanding and Predicting the Fate of Semivolatile Organic Pesticides in a Glacier-Fed Lake Using a Multimedia Chemical Fate Model

Understanding and Predicting the Fate of Semivolatile Organic Pesticides in a Glacier-Fed Lake Using a Multimedia Chemical Fate Model

09/19/2017

Xiaolin Wu, Cleo L. Davie-Martin, Christine Steinlin, Kimberly J. Hageman, Nicolas J. Cullen, and Christian Bogdal: Melting glaciers release previously ice-entrapped chemicals to the surrounding environment. As glacier melting accelerates under future cli...

A bipyridine-ligated zinc(II) complex with bridging flavonolate ligation: synthesis, characterization, and visible-light-induced CO release reactivity

A bipyridine-ligated zinc(II) complex with bridging flavonolate ligation: synthesis, characterization, and visible-light-induced CO release reactivity

09/01/2017

Shayne Sorenson, Marina Popova, Atta M. Arifb and Lisa M. Berreau: Metal–flavonolate compounds are of significant current inter­est as synthetic models for quercetinase enzymes and as bioactive compounds of importance to human health. Zinc–3-hy­droxy­fla...

Universal interrelation between measures of particle and polymer size

Universal interrelation between measures of particle and polymer size

07/06/2017

F. Vargas-Lara, M.L. Mansfield, J.F. Douglas: This paper explores interrelationships between the intrinsic viscosity, the hydrodynamic (or Stokes) radius, and the radius of gyration of polymers and particles.

Transition states and control of substrate preference in the promiscuous phosphatase PP1

Transition states and control of substrate preference in the promiscuous phosphatase PP1

07/05/2017

Yuan Chu, Nicholas H. Williams, and Alvan C. Hengge : Catalytically promiscuous enzymes are an attractive frontier for biochemistry, because enzyme promiscuities not only plausibly explain enzyme evolution through the mechanism of ge...

Effects of molecular structure and solvent polarity on adsorption of carboxylic anchoring dyes onto TiO2 particles in aprotic solvents

Effects of molecular structure and solvent polarity on adsorption of carboxylic anchoring dyes onto TiO2 particles in aprotic solvents

06/24/2017

Hui Fang, Bolei Xu, Xia Li, Danielle L. Kuhn, Zander Zachary, Guocai Tian, Victoria Chen, Rosa Chu∥, Brendan G. DeLacy, Yi Rao , and Hai-Lung Dai: Interactions of molecules with the surface of TiO2 particles are of fundamental and technological importance...

Conformational regulation of CRISPR-associated nucleases

Conformational regulation of CRISPR-associated nucleases

06/15/2017

Jackson, R., van Erp, P.B, Sternberg, S.H, Wiedenheft, B.: Adaptive immune systems in bacteria and archaea rely on small CRISPR-derived RNAs (crRNAs) to guide specialized nucleases to foreign nucleic acids. The activation of these nucleases is controlled ...

Detection and quantification of gas-phase oxidized mercury compounds by GC/MS

Detection and quantification of gas-phase oxidized mercury compounds by GC/MS

05/18/2017

Jones C.P., Lyman S.N., Jaffe D.A., Allen T., O’Neil T.L.: Most mercury pollution is emitted to the atmosphere, and the location and bioavailability of deposited mercury largely depends on poorly understood atmospheric chemical reactions that convert elem...

Quantification of low molecular weight n-alkanes in lake sediment cores for paleoclimate studies

Quantification of low molecular weight n-alkanes in lake sediment cores for paleoclimate studies

05/16/2017

Aebig, C.H.F., Curtin, L., Hageman, K.J., Moy, C.M., Beltran, C.: Organic biomarkers, such as n-alkanes, can be used as proxies in a range of paleoclimate and paleoenvironmental investigations. n-Alkanes accumulate in lacustrine sediments and can therefor...

A stable compound of helium and sodium at high pressure

A stable compound of helium and sodium at high pressure

02/06/2017

Xiao Dong, Artem R. Oganov, Alexander F. Goncharov, Elissaios Stavrou, Sergey Lobanov, Gabriele Saleh, Guang-Rui Qian, Qiang Zhu, Carlo Gatti, Volker L. Deringer, Richard Dronskowski, Xiang-Feng Zhou, Vitali B. Prakapenka, Zuzana Konôpková, Ivan A. Popov,...

Thermal and elastic characterization of glassy carbon thin films by photoacoustic measurements

Thermal and elastic characterization of glassy carbon thin films by photoacoustic measurements

01/23/2017

D.D. Markushev, J. Ordonez-Miranda, M.D. Rabasovi´c, M. Chirtoc, D.M. Todorovi´c, S.E. Bialkowski, D. Korte, and M. Franko: A portable photoacoustic device is designed and applied to measure thermal diffusivity and linear thermal expansion coefficient of ...

External stimuli responsive 2D charge transfer polymers

External stimuli responsive 2D charge transfer polymers

01/23/2017

Zhuolei Zhang, Beibei Xu, Bolei Xu, Lei Jin, Hai-Lung Dai, Yi Rao, Shenqiang Ren: 2D conjugated charge-transfer polymers hold the fundamental importance of both atomically defined molecular structures and unique spatial confinement for distinctive and exo...