Publications
Anisotropic Geminate and Non-Geminate Recombination of Triplet Excitons in Singlet Fission of Single Crystalline Hexacene
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
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
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
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
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
o-Quinone phenalenyl derivatives as expedient ligands for the design of magnetically active metal complexes: A computational study
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](/chemistry_publications/images/12.22.2019.JPG)
Expansion of aromaticity magnetic criteria on multi‐layer structures. Magnetic response and spherical aromaticity of Matryoshka‐like [Sn@Cu12@Sn20]12‐ cluster
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
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](/chemistry_publications/images/12.18.2019.JPG)
Spherical aromaticity of all‐metal [Bi@In8Bi12]3‐/5‐ clusters
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
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
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
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
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
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)
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
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 flexible N-terminus of BchL protects its [4Fe-4S] cluster in oxygenic environments and autoinhibits activity](/chemistry_publications/images/11.12.2019.JPG)
The flexible N-terminus of BchL protects its [4Fe-4S] cluster in oxygenic environments and autoinhibits activity
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
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
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
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
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
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
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...
Establishing a Thermodynamic Landscape for the Active Site of Mo-Dependent Nitrogenase
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
Extracellular vs Instracellular Delivery of CO: Does It Matter for a Stable, Diffusible Gasotransmitter?
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
Anisotropic Singlet Fission in Single Crystalline Hexacene
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
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
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
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
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)
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
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
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
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
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
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
Theoretical insight into a feasible strategy of capturing, storing and releasing toxic HCN at the surface of doped BN-sheets by charge modulation
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
Superoctahedral two-dimensional metallic boron with peculiar magnetic properties
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
Phototrophic N2 and CO2 Fixation Using a Rhodopseudomonas palustris-H2 Mediated Electrochemical System With Infrared Photons
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
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
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
A pH-Neutral, Metal-Free Aqueous Organic Redox Flow Battery Employing an Ammonium Anthrquinone Anolyte
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
Vibronic fingerprint of singlet fission in hexacene
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
Effects of Halogen, Chalcogen, Pnicogen, and Tetrel Bonds on IR and NMR Spectra
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
Chronic Toxicities of Neonicotinoids to Nymphs of the Common New Zealand Mayfly Deleatidium spp.
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
Violation of Electrostatic Rules: Shifting the Balance between Pnicogen Bonds and Lone Pair−π Interactions Tuned by Substituents
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
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
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
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
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
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
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
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...
Retardation of Crystallization through the Addition of Dairy Phospholipids
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
Mo-, V-, and Fe-Nitrogenases Use a Universal Eight-Electron Reductive-Elimination Mechanism To Achieve N2 Reduction
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
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
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
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
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
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
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
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
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
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 shigella type three secretion system activation
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
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
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
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-](/chemistry_publications/images/StructureandBonding_JournalCover.JPG)
Structure and Bonding in [Sb@In8Sb12]3- and [Sb@In8Sb12]5-
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
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
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
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
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
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...
Interactions of (MY)6 (M = Zn, Cd; Y = O, S, Se) quantum dots with N-bases
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
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
Multiple local o-aromaticity of nonagermanide clusters
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
On the capability of metal-halogen groups to participate in halogen bonds
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
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
Hydrated Sulfate Clusters SO4^2-(H2O)n (n = 1-40): Charge Distribution Through Solvation Shells and Stabilization
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
Electrochemical Dinitrogen Reduction to Ammonia by Mo2N: Catalysis or Decomposition?
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
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
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
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
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
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
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
A 1.51 V pH neutral redox flow battery towards scalable energy storage
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
Air Analysis l Sampling
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
Molecular rotation in 3 dimensions at an air/water interface using femtosecond time resolved sum frequency generation
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
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
Structural and Functional Characterization of Sulfonium Carbon-Oxygen Hydrogen Bonding in the Deoxyamino Sugar Methyltransferase TylM1
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
Transition State Analysis of the Reaction Catalyzed by the Phosphotriesterase from Sphingobium sp. TCM1
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...
Heme-Derived Bilins
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-](/chemistry_publications/images/2.22.19.JPG)
Two names of stability: Spherical aromatic or superatomic intermetalloid cluster [Pd3Sn8Bi6]4-
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
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
Hexacoordinated Tetrel-Bonded Complexes between TF4 (T=Si, Ge, Sn, Pb) and NCH: Competition between σ- and π-Holes
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
Inhibition of Connexion Hemichannels by New Aminoglycosids without Antibiotic Activity
Cheng-Wei T. Chang, Yagya P. Subedi, Madher N. Alfindee
Tracking CO Release in Cells via the Luminescence of Donor Molecules and/or their By-Products
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 Pseudomonas aeruginosa Arylsulfatase
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
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
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)
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
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
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
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
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
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
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
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 Azospirillum brasilense
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
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 Azotobacter vinelandii
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
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
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
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
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
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
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
Heather B. Case and Nicholas E. Dickenson
Carbene triel bonds between TrR3 (Tr = B, Al) and N-heterocyclic carbenes
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
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
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
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
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...
A new era for electron bifurcation
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
Synthesis and biological activity investigation of azole and quinone hybridized phosphonates
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...
Visible-light-activated quinolone carbone-monoxide-releasing molecule: prodrug and albumin-assisted delivery enables anticancer and potent anti-inflammatory effects
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
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
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
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
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
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
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
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...
Excitonic and confinement effects of 2D layered (C10H21NH3) 2PbBr4 single crystals
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...
Thermodynamic measures of binding strength in pnicogen, chalcogen, halogen, and hydrogen bonds
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...
Electrolyzer design for flexible decoupled water splitting and organic upgrading with electron reservoirs
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
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
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
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
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
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†
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
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
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
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
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
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
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
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
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
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
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
Yuan Chu, Nicholas H. Williams, and Alvan C. Hengge
Effects of molecular structure and solvent polarity on adsorption of carboxylic anchoring dyes onto TiO2 particles in aprotic solvents
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
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
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
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
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,...
External stimuli responsive 2D charge transfer polymers
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...
Thermal and elastic characterization of glassy carbon thin films by photoacoustic measurements
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 ...
