Quantum Theory Of Atoms In Molecules Research Articles

Synthesis, solvent-solute interactions (polar and non-polar), spectroscopic insights, topological aspects, Fukui functions, molecular docking, ADME, and donor-acceptor investigations of 2-(trifluoromethyl)benzimidazole: A promising candidate for antitumor pharmacotherapy

The favorite heteroatom-containing compound, 2-(trifluoromethyl) benzimidazole (2TFMBI), was synthesized and experimentally characterized using spectroscopic techniques. Density Functional Theory (DFT) with B3LYP/6–311++G(d,p) basis set was employed to simulate geometrical parameters, vibrational spectra, electronic spectra, chemical shifts, and other properties of 2TFMBI. Solvent effects, including aprotic polar (aniline and DMSO), protic polar (methanol and water), and non-polar (carbon tetrachloride, chloroform, cyclohexane, and toluene), on electronic properties, frontier molecular orbitals (FMO), and Molecular Electrostatic Potential Surface (MESP) were analyzed. Additionally, Natural Bond Orbital (NBO) and Mulliken population analysis were simulated to better understand the structural aspects of 2TFMBI. The energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) confirms the compound's high reactivity and charge transfer. In-silico Absorption, Distribution, Metabolism, and Excretion (ADME) indices were determined to have potential pharmacokinetic attributes and biological properties. A set of topological analyses, including Electron Localization Function (ELF), Local Orbital Locator (LOL), Non-Covalent Interaction (NCI), Reduced Density Gradient (RDG), and Quantum Theory of Atoms in Molecules (QTAIM) was performed to reveal weak interactions within the compound, spanning both chemical functionalities and delocalized zones. Furthermore, molecular docking analysis was performed to examine the potential biological activity against tumor-inducing proteins H-RASGTP and H-RASGDP, endorsing the antitumor efficacy of 2TFMBI.

Methyl 4-pyridyl ketone thiosemicarbazone (4-PT) as an effective and safe inhibitor of mushroom tyrosinase and antibrowning agent

Enzymatic browning is of concern as it can affect food safety and quality. In this study, an effective and safe tyrosinase inhibitor and anti-browning agent, methyl 4-pyridyl ketone thiosemicarbazone (4-PT), was synthesised and characterised using Fourier-transform infrared (FTIR) spectroscopy, CHNS elemental analysis, and proton (1H) and carbon-13 (13C) nuclear magnetic resonance (NMR) spectroscopy. The vibrational frequencies of 4-PT were studied theoretically using vibrational energy distribution analysis (VEDA). Density functional theory (DFT) was applied to elucidate its chemical properties, including the Mulliken atomic charges, molecular electrostatic potential (MEP), quantum theory of atoms in molecules (QTAIM) and reduced density gradient non-covalent interactions (RDG-NCIs). Moreover, 4-PT was compared with kojic acid in terms of its effectiveness as a tyrosinase inhibitor and anti-browning agent. The toxicity and physicochemical properties of 4-PT were predicted via ADME evaluation, which proved that 4-PT is safer than kojic acid. Experimentally, 4-PT (IC50 = 5.82 μM, browning index (10 days) = 0.292 ± 0.002) was proven to be an effective tyrosinase inhibitor and anti-browning agent compared to kojic acid (IC50 = 128.17 μM, browning index (10 days) = 0.332 ± 0.002). Furthermore, kinetic analyses indicated that the type of tyrosinase inhibition is a mixed inhibition, with Km and Vmax values of 0.85 mM and 2.78 E-09 μM/s, respectively. Finally, the mechanism of 4-PT for tyrosinase inhibition was proven by 1D, second derivative and 2D IR spectroscopy, molecular docking and molecular dynamic simulation approaches.

Adsorption of some cationic dyes onto two models of graphene oxide

Context:The search for highly efficient adsorbent materials remains a significant requirement in the field of adsorption for wastewater treatment. Computational study can highly contribute to the identification of efficient material. In this work, we propose a computational approach to study the adsorption of four cationic basic dyes, basic blue 26 (BB26), basic green 1 (BG1), basic yellow 2 (BY2), and basic red 1 (BR1), onto two models of graphene oxide as adsorbents. The main objectives of this study are the assessment of the adsorption capacity of the graphene oxide towards basic dyes and the evaluation of the environmental and temperature effects on the adsorption capacity. Quantum theory of atoms in molecules (QTAIM) analysis has been used to understand the interactions between the dyes and graphene oxides. In addition, adsorption free energies of the dyes onto graphene oxides are calculated in gas and solvent phases for temperatures varying from 200 to 400 K. As a result, the adsorption free energy varies linearly depending on the temperature, highlighting the importance of temperature effects in the adsorption processes. Furthermore, the results indicate that the environment (through the solvation) considerably affects the calculated adsorption free energies. Overall, the results show that the two models of graphene oxide used in this work are efficient for removing dyes from wastewater.Methods:We have optimized the complexes formed by the interaction of dyes with graphene oxides at the PW6B95-D3/def2-SVP level of theory. The SMD solvation model realizes the implicit solvation, and water is used as the solvent. Calculations are performed using the Gaussian 16 suite of program. QTAIM analysis is performed using the AIMAll program. Gibbs free energies as function of temperature are calculated using the TEMPO program.

Linear and Nonlinear Optical Responses of Nitrobenzofurazan-Sulfide Derivatives: DFT-QTAIM Investigation on Twisted Intramolecular Charge Transfer.

In this study, we report on the green fluorescence exhibited by nitrobenzofurazan-sulfide derivatives (NBD-Si, i = 1-4). The optical responses of these studied compounds in a polar methanol solvent were simulated by the use of time-dependent density functional theory (TD-DFT) employing the Becke-3-Parameter-Lee-Yang-Parr (B3LYP) functional along with the 6-31G(d,p) basis set. The computed energy and oscillator strength (f) results complement the experimental results. The band gap was calculated as the difference between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO). Additionally, the density of states (DOS) was computed, providing a comprehensive understanding of the fundamental properties of these materials and further corroborating the experimental data. When the experimental data derived from ultraviolet/visible (UV/visible) and fluorescence spectroscopic techniques and those from simulated spectra are analyzed, the extracted values match up adequately. In addition, the NBD-sulfide compounds exhibit a large Stokes shift up to 85 nm in a polar methanol solvent. They are hypothesized to represent a novel paradigm of excited-state intramolecular charge transfer (ICT). To understand the intrinsic optical properties of NBD-Si materials, an ICT was identified, and its direction within the molecule was evaluated using the ratio of βvect and βtotal, values extracted from the computed nonlinear optical (NLO) properties. Moreover, the reduced density gradient (RDG)-based noncovalent interactions (NCIs) were employed to characterize the strength and type of NBD-Si interactions. Furthermore, noncovalent interactions were identified and categorized using the Quantum Theory of Atoms in Molecules (QTAIM) analysis. Ultimately, the combination of Hirshfeld surface analysis and DFT calculations was utilized to enhance the characterization and rationalization of these NCIs.

Unveiling regularities of B12N12-X nanocages as a drug delivery vehicle for the nitrosourea: The influence of periods and groups

Cancer treatment has long been a topic of interest and the use of small molecule targeted drugs has highlighted the potential of nanomaterials as carriers for reducing drug side effects. In this study, we investigated the decoration of various transition metals on B12N12 nanocages as parameters for nitrosourea drug delivery carriers using density functional theory (DFT) and time-dependent DFT (TDDFT) calculations. We examined the electronic properties, topological analysis, electrostatics, and van der Waals (vdW) potential analysis. Our findings revealed a gradual weakening of the interaction between transition metals in same period and B12N12 nanocages, which could affect the adsorption energy of the Nu drug. Quantum theory of atoms in molecules (QTAIM), non-covalent interactions (NCI) and vdW potential analysis unveil that there are weak non-covalent interactions between metals and O atom and the interaction between Nu and B12N12 nanocages plays significant role in drug adsorption. Compared to the free drug, the adsorption of drugs on nano-cages could reduce the HOMO-LUMO energy gap and chemical hardness of the complexes, facilitating electron transfer and indicating activity at the target site. The charge-transfer between drug and B12N12 nanocages can effectively change the adsorption character of drug. Computed results shown that compared with other carriers, BN_Ni and BN_Pt exhibit better performances, which possess moderate recovery times at body temperature. This research evaluates the drug delivery capabilities of transition metal-decorated B12N12 nanocages for nitrosourea (Nu) in gas and aqueous environments, providing a rational perspective for designing novel nitrosourea drug carriers.

Structural properties of newly 4,7-dihydroxycoumarin derivatives as potential inhibitors of XIIa, Xa, IIa factors of coagulation

Some coumarin derivatives show notable anticoagulant properties through their ability to interrupt the enzymatic function of vitamin K epoxide reductase. The current challenge lies in the development of novel derivatives that are more efficient and less harmful, specifically targeting the direct inhibition of coagulation factors. This study examined the direct inhibitory potential of two recently synthesized coumarin derivatives, 3-(1-(3-hydroxy-4-methoxyphenyl)-amino)-ethyldiene)-2,4-dioxochroman-7-yl acetate (A-3OH) and 3-(1-(4-hydroxy-3-methoxyphenyl)-amino)-ethyldiene)-2,4-dioxochroman-7-yl acetate (A-4OH), according to coagulation factors IIa, Xa, and XIIa. Accurately defining the structural properties of compounds is of great importance for a comprehensive understanding of the biological activity of pharmaceutical agents. In regard, this study aimed to analyze the structural (Potential Energy Surface (PES)), spectroscopic (FT-IR, NMR, and UV–Vis), and electronic properties (Quantum Theory of Atoms in Molecules (QTAIM)) of two newly synthesized compounds. These properties are determined using a combination of experimental and theoretical methods (B3LYP-D3BJ/6–311++G(d,p) level of theory). The investigated compounds deviate from planarity based on the results of structural properties. The results of QTAIM analysis show the presence of partially covalent hydrogen bonds and closed-shell van der Waals interactions that stabilize the examined compounds. Based on the large correlation coefficient (R) and low mean absolute error (MAE) of the spectroscopic data showed that the applied level of theory effectively replicated the experimental finding. The results from the molecular docking study suggest that both compounds demonstrate similar inhibitory effects on IIa when compared to the standard inhibitor dabigatran (DAB). The efficacy of A-3OH in inhibiting Xa is similar to that of conventional inhibitors apixaban (API), and rivaroxaban (RIV). The observed inhibitory effect of both compounds on coagulation factor XIIa was more potent than that of the conventional co-crystallized inhibitor. The results of this study add to the understanding of the structure-activity relationship of coumarin derivatives and provide possibilities for enhancing anticoagulant therapy and clinical outcomes for coagulation-related illnesses. The findings lay a foundation for further in vitro and in vivo investigations into the anticoagulant activities of the compounds, contributing to their potential pharmaceutical application.

Computational Insight into the Nature and Strength of the π-Hole Type Chalcogen∙∙∙Chalcogen Interactions in the XO2∙∙∙CH3YCH3 Complexes (X = S, Se, Te; Y = O, S, Se, Te).

In recent years, the non-covalent interactions between chalcogen centers have aroused substantial research interest because of their potential applications in organocatalysis, materials science, drug design, biological systems, crystal engineering, and molecular recognition. However, studies on π-hole-type chalcogen∙∙∙chalcogen interactions are scarcely reported in the literature. Herein, the π-hole-type intermolecular chalcogen∙∙∙chalcogen interactions in the model complexes formed between XO2 (X = S, Se, Te) and CH3YCH3 (Y = O, S, Se, Te) were systematically studied by using quantum chemical computations. The model complexes are stabilized via one primary X∙∙∙Y chalcogen bond (ChB) and the secondary C-H∙∙∙O hydrogen bonds. The binding energies of the studied complexes are in the range of -21.6~-60.4 kJ/mol. The X∙∙∙Y distances are significantly smaller than the sum of the van der Waals radii of the corresponding two atoms. The X∙∙∙Y ChBs in all the studied complexes except for the SO2∙∙∙CH3OCH3 complex are strong in strength and display a partial covalent character revealed by conducting the quantum theory of atoms in molecules (QTAIM), a non-covalent interaction plot (NCIplot), and natural bond orbital (NBO) analyses. The symmetry-adapted perturbation theory (SAPT) analysis discloses that the X∙∙∙Y ChBs are primarily dominated by the electrostatic component.

The Theoretical Investigation by QTAIM Approach to Chemical Bonding of a Di-Rhenium Bis(Triphenylphosphine) Carbonyl Cluster Containing Sulfuric and Hydrido Bridge: [Re2(CO)6(μ-S)(μ-H)(PPh3)2

Scientists used the quantum theory of atoms in molecules (QTAIM) to calculate and interpret various electron density parameters for a di-rhenium bis(triphenylphosphine) carbonyl cluster containing sulfuric and hydrido bridge: [Re2(CO)6(μ-S)(μ-H)(PPh3)2]. They analyzed the bond critical points and compared them with data from previous organometallic system studies. The researchers were able to compare the topological processes of different atom-atom interactions based on these results.
 The calculations showed that there were no bond critical points or identical bond paths between Re-Re in the core of the cluster. The electron density distribution was affected by the position of bridging hydride and sulfur atoms coordinated to Re-Re, which significantly affected the bonds between these transition metal atoms. However, the calculations did confirm the presence of a 6c–8e bonding interaction delocalized over HRe2SP2 in the cluster.
 The scientists found that the Re-H and Re-S bonds in this cluster exhibited typical closed-shell interactions, with small values for ρ(b) and Laplacian ∇2ρ(b) above zero and small positive values for total energy density H(b). Similarly, the bond interactions between phosphine metal atoms and the C atoms of the phenyl ring ligands showed properties similar to open-shell interactions in the QTAIM classification.

An extensive experimental and DFT studies on highly selective detection of nitrobenzene through deferasirox based new fluorescent sensor

A deferasirox based substituted triazole amine sensor TAD has been synthesized for the highly selective detection of nitrobenzene in real samples. Sensor TAD exhibited selective quenching response against nitrobenzene among the other nitroaromatic compounds (NACs). Photoinduced electron transfer (PET) process was devised as plausible sensing mechanisms which was supported via UV–visible and fluorescence spectroscopy, 1H NMR titration experiment, density functional theory (DFT) analysis and Job’s plot. Non-covalent interaction (NCI) analysis and Bader’s quantum theory of atoms in molecules (QTAIM) analysis were performed to investigate the presence of non-covalent interactions and symmetry perturbation theory (SAPT0) was performed for energy decomposition and quantitative analysis of interaction energies between sensor TAD and NB. Furthermore, sensor TAD was practically applied for the identification of NB in real samples.

Exploring boron nitride nanostructures for effective pyrazinamide drug delivery: A DFT study

In present investigation, interactions of pyrazinamide molecule with boron nitride nanocones (BNC), boron nitride nanosheet (BNS), and boron nitride nanotube (BNT) as nanostructures have been studied for drug delivery applications via DFT computations. For DFT computations on studied models, two phases (aqueous and gaseous) have been regarded. In both phases, a stabilized complex of nanostructures and pyrazinamide has been obtained based on adsorption energy (Eads) values. According to negative Eads value, an exothermic reaction has been observed. The hydrogen bonding has found in all complexes due to low and positive values of electron density in critical points of bond (ρr) based on the quantum theory of atoms in molecules (QTAIM). Computations outcomes also revealed that there were weak interaction forces for successful and significant unloading of curcumin from carriers in target sites. In order to assess impact of molecular adsorption over electronic features of nanostructures, density of states (DOS) has been analyzed, and outcomes indicated that BNC was more proximate to Fermi energy compared to other nanomaterials. In gaseous phase, Eads values were greater than aqueous phase, which indicates a more robust interaction of molecules with nanostructures. Compared to other nanostructures, curcumin had stronger interaction with BNC based on Eads values. At the end of pyrazinamide adsorption, ΔEg values were – 1.17, − 0.27, and −0.19 eV for BNC, BNS, and BNT, respectively, which reveal that BNC had more sensitivity than BNS and BNT. Based on computations conducted in present work, nanostructures could potentially be employed to deliver pyrazinamide.

Unraveling non-covalent interactions in bis-chalcone: A crystallographic and theoretical studies

A new bis-chalcone THXA, (2E,2′E)-1,1′-(((1,4-phenylenebis(methylene))bis(oxy))bis(2,1-phenylene))bis(3-(thiophen-2-yl)prop‑2-en-1-one) is synthesized and characterized by spectroscopic and single crystal X-ray diffraction techniques from chalcone (E)-1-(2-hydroxyphenyl)-3-(thiophen-2-yl)prop‑2-en-1-one) and xylene dibromide. The intermolecular non-covalent interactions such as π···π, CH···S and CH···π participate decisive roles in the development of supramolecular structures. An inclusive Hirshfeld surface analysis discloses the presence of intermolecular non-covalent interactions. The 2D fingerprint plots reveal individual atom's percentage contributions in construction of the non-covalent interactions. Hirshfeld energy framework study affirms dominance of the dispersive π-π interaction in THXA. Further, energetic estimation for non-covalent interactions of dimeric unit has been calculated through density functional theory (DFT). The molecular electrostatic potential (MEP) surfaces help to describe the charge distribution in THXA. Additionally, the non-covalent interactions in THXA are also examined by computational tools like non-covalent interaction (NCI) plot index and quantum theory of atoms in molecules (QTAIM) analysis.

Structures of DMSO clusters and quantum cluster equilibrium (QCE)

Dimethylsulfoxide (DMSO) clusters are crucial for understanding processes in liquid DMSO. Despite its importance, DMSO clusters have received negligible attention due to the complexity of their potential energy surfaces (PESs). In this work, we explored the PESs of the DMSO clusters from dimer to decamer, starting with classical molecular dynamics, followed by full optimizations at the PW6B95-D3/def2-TZVP level of theory. In addition, the binding energies, the binding enthalpy per DMSO, and the quantum theory of atoms in molecules (QTAIM) analysis of the most stable isomers are reported. Temperature effects on the stability of the isomers have also been assessed. After thoroughly exploring the PESs of the DMSO clusters, 159 configurations have been used to apply the quantum cluster equilibrium (QCE) theory to liquid DMSO. The quantum cluster equilibrium theory has been applied to determine the liquid properties of DMSO from DMSO clusters. Thus, using the QCE, the population of the liquid DMSO, its infrared spectrum, and some thermodynamic properties of the liquid DMSO are predicted. The QCE results show that the population of the liquid DMSO is mainly dominated by the DMSO dimer and decamer, with the contribution in trace of the DMSO monomer, trimer, tetramer, pentamer, and octamer. More interestingly, the predicted infrared spectrum of liquid DMSO is in qualitative agreement with the experiment.

Cooperativity and topological hydrogen bonding in aromatic diol complexes

AbstractComplexes of three aromatic diols, catechol, naphthalene‐1,8‐diol, and fluorene‐4,5‐diol, with a series of hydrogen bond acceptors (HBAs) that have oxygen, nitrogen, and sulfur acceptor atoms, have been studied by density functional theory (DFT) at the B3LYP/6‐311+G(d,p) level. Binding energies, geometries, infrared spectroscopic (IR) frequencies, nuclear magnetic resonance (NMR) shifts, and measures of the electron density distribution from the Quantum Theory of Atoms in Molecules (QTAIM) are evaluated and compared with data for the corresponding monohydroxy compounds (monols), phenol, naphth‐1‐ol, and fluorene‐4‐ol, in order to assess the importance of cooperativity between intramolecular and intermolecular hydrogen bonding. All measures for all complexes show positive cooperativity whereby both the intermolecular and intramolecular hydrogen bonds are strengthened upon complexation. Cooperativity is weak for catechol and strong for the other two diols and, for all diols, increases with the hydrogen bond basicity of the acceptor. Correlations of IR and NMR metrics against binding energies for a single HBA and all six monols and diols are excellent, but attempts to correlate the same metrics for all HBAs and a single donor are frustrated by differences in intermolecular hydrogen bonding, depending notably on the identity of the acceptor atom in the HBA. Atom–atom interaction energies, calculated by the Interacting Quantum Atoms approach, are used to discuss the covalency of both types of hydrogen bond.

Halogen Bonding in Brominated BODIPY Crystals: a Crystallographic and Computational Study.

The study of halogen bonds (XBs) has been a subject of great interest in recent years due to its clear application in catalysis, liquid crystals, and crystal engineering. In this study we analyzed the intermolecular interactions, in particular halogen bonds in BODIPYs with increasing number of bromine atoms. The computational study included analyses through three different methods: the first approach of close contacts provided by Mercury, then the expanded approach of the electron density partition of the molecules in the crystals provided by the analysis of Hirshfeld surfaces, and finally, the approach of the Quantum Theory of Atoms in Molecules (QT-AIM) to characterize the non-covalent interactions through finding electron density critical points between atoms and between neighboring molecules. The use of different computational methods allowed to gain insight on the interactions directing the crystal packing as the number of bromine atoms increase in the BODIPY moiety. Monocoordinated and bifurcated halogen bonds involving halide/halide were found. The penta-brominated BODIPY showed four-center cyclic nodes where each node is linked via XBs. This kind of motifs can be useful in supramolecular chemistry and self-assembly.

Optoelectronic Characterisation and Theoretical Insight into the Binding Mechanism of D‐π‐A Triphenylamine‐Organic Dyes for Dye Sensitized Solar Cells

AbstractThere has been a notable surge of interest in the field of dye sensitized solar cells (DSSCs) in recent years due to their remarkable performance in indoor/ambient and diffused light conditions. A significant portion of these highly efficient indoor DSSCs employs organic dyes based on triphenylamine. In this study, we present the findings of our investigation on two metal‐free D‐π‐A organic dyes, namely triphenylamine (YK 10) and hexyloxy‐substituted triphenylamine (YK 11), serving as electron donors. These dyes feature a 3,3′′‐dioctyl‐2,2′:5′,2′′‐terthiophene π‐spacer and cyanoacetic acid as the anchoring group. In order to comprehensively assess the relationship between the molecular structure, physical properties, and solar cell performance, we conducted in‐depth analysis involving photophysical, electrochemical, and theoretical studies. Our results indicate that these dyes possess the ability to effectively capture light within the visible spectrum and exhibit suitable energetic characteristics for efficient electron injection and dye regeneration. Through the utilization of density functional theory (DFT) modeling, we explored the interfacial adsorption configuration of the dyes on the TiO2 semiconductor, revealing the involvement of the cyano group in the anchoring mechanism for both sensitizers. Moreover, the intramolecular S…CN interaction in these dyes was verified through topological quantum‐theory‐of‐atom‐in‐molecule (QTAIM) analysis, which facilitates additional intramolecular charge transfer pathways. The DSSCs incorporating YK 10 and YK 11 demonstrated power conversion efficiencies (PCEs) of 6.42 % and 6.22 %, respectively, under full sun illumination (100 mW/cm2). Remarkably, under both standard 1000 lux CFL and LED illumination conditions, YK 11 exhibited superior performance with PCEs of 8.29 % and 5.89 %, respectively, surpassing the efficiencies of YK 10, which achieved 7.50 % and 5.09 % efficiencies under the same conditions.

In-Silico Aided Screening and Characterization Results in Stability Enhanced Novel Roxadustat Co-Crystal

Roxadustat (RXD) is an approved drug substances for the treatment of renal anemia. It has poor aqueous solubility and photochemical stability. This study employs a comprehensive approach to enhance the stability and physicochemical properties RXD through coformer selection and characterization. The investigation integrates delta pKa analysis, molecular complementary assessment, molecular electrostatic potential surface analysis, and machine learning techniques to predict potential co-crystal formation and binding interactions between drug molecules and coformers. The co-crystal screening which lead to in a novel RXD-nicotinamide co-crystal (RXD-NA). Experimental characterization underscores the physical and chemical stability of the co-crystals. To elucidate the supramolecular synthons and understand the intermolecular interactions in the RXD-NA co-crystal, Hirshfeld surfaces analysis, quantum theory of atoms in molecules (QTAIM) analysis and non-covalent interaction (NCI) analysis were performed. Computational analysis of photo-isomer formation aligns with experimental observations, further enhancing our understanding of RXD-coformer interactions. RXD-NA co-crystal was found photo-chemically stable as compared to free base API drug substance. This integrated methodology provides a systematic framework for informed co-crystal design, holding promise for optimizing RXD formulations based on molecular interactions and stability considerations. Consequently, this study contributes valuable insights to the field of rational drug design and formulation optimization.

Molecular insight into endosulfan degradation by Ese protein from Arthrobacter: Evidence-based structural bioinformatics and quantum mechanical calculations.

Endosulfan is an organochlorine insecticide widely used for agricultural pest control. Many nations worldwide have restricted or completely banned it due to its extreme toxicity to fish and aquatic invertebrates. Arthrobacter sp. strain KW has the ability to degrade α, β endosulfan and its intermediate metabolite endosulfate; this degradation is associated with Ese protein, a two-component flavin-dependent monooxygenase (TC-FDM). Employing in silico tools, we obtained the 3D model of Ese protein, and our results suggest that it belongs to the Luciferase Like Monooxygenase family (LLM). Docking studies showed that the residues V59, V315, D316, and T335 interact with α-endosulfan. The residues: V59, T60, V315, D316, and T335 are implicated in the interacting site with β-endosulfan, and the residues: H17, V315, D316, T335, N364, and Q363 participate in the interaction with endosulfate. Topological analysis of the electron density by means of the Quantum Theory of Atoms in Molecules (QTAIM) and the Non-Covalent Interaction (NCI) index reveals that the Ese-ligands complexes are formed mainly by dispersive forces, where Cl atoms have a predominant role. As Ese is a monooxygenase member, we predict the homodimer formation. However, enzymatic studies must be developed to investigate the Ese protein's enzymatic and catalytic activity.

Strukturen, Bindungsanalyse und Reaktivität eines dikationischen Digallens und eines Diindens, die trans‐gefaltete Ditetrylene nachahmen

AbstractDie Reaktion von Bisdicyclohexylphosphinoethan (dcpe) und den subvalenten MI‐Quellen [MI(PhF)2][pf] (M=Ga+, In+; [pf] −=[Al(ORF)4]−; RF=C(CF3)3) ergab die Salze [{M(dcpe)}2][pf]2, die die ersten bisher dokumentierten dikationischen, trans‐gefalteten Digallen‐ und Diindenstrukturen enthalten. Die nicht‐klassischen MI⇆MI‐Doppelbindungen sind überraschend kurz und zeigen eine ditetrylenartige Struktur. Die Bindungssituation wurde durch quantenchemische Berechnungen, QTAIM‐ (Quantum Theory of Atoms in Molecules) und EDA‐NOCV‐Analysen (Energy Decomposition Analysis with the combination of Natural Orbitals for Chemical Valence) umfassend analysiert und mit derjenigen in den isoelektronischen und isostrukturellen, aber neutralen Digermenen und Distannenen verglichen. Das gelöste [{Ga(dcpe)}2]2+([pf]−)2 reagiert unter milden Bedingungen bei Raumtemperatur mit 1‐Hexen, Cyclooctin, Diphenyldisulfid und Diphenylphosphan. Diese Reaktivität wird analysiert und rationalisiert.

Structures, Bonding Analyses and Reactivity of a Dicationic Digallene and Diindene Mimicking trans-bent Ditetrylenes.

The reaction of bisdicyclohexylphosphinoethane (dcpe) and the subvalent MI sources [MI (PhF)2 ][pf] (M=Ga+ , In+ ; [pf]- =[Al(ORF )4 ]- ; RF =C(CF3 )3 ) yielded the salts [{M(dcpe)}2 ][pf]2 , containing the first dicationic, trans-bent digallene and diindene structures reported so far. The non-classical MI ⇆MI double bonds are surprisingly short and display a ditetrylene-like structure. The bonding situation was extensively analyzed by quantum chemical calculations, QTAIM (Quantum Theory of Atoms in Molecules) and EDA-NOCV (Energy Decomposition Analysis with the combination of Natural Orbitals for Chemical Valence) analyses and is compared to that in the isoelectronic and isostructural, but neutral digermenes and distannenes. The dissolved [{Ga(dcpe)}2 ]2+ ([pf]- )2 readily reacts with 1-hexene, cyclooctyne, diphenyldisulfide, diphenylphosphine and under mild conditions at room temperature. This reactivity is analyzed and rationalized.

Comparative analysis of interaction of ionic liquids with porous and non-porous electrode materials

Fascinating properties of ionic liquids such as their higher ionic conductivity, lower vapor pressure, high thermal and electrochemical stability, make them promising candidates as electrolytes for novel energy storage devices. Interaction of ionic liquids (ILs) as electrolytes with electrode is crucial for optimizing the efficiency of energy storage devices. Herein, we report the interaction mechanism of ionic liquids 1-3 dimethylimidazolium halide (1,3-DMIX) on porous covalent triazine frameworks (CTF-0) and non-porous carbon nitride (C4N) electrode materials. Molecular electrostatic potential (MEP) analysis is performed for the prediction of interacting sites on studied electrolytes and electrode materials. Significant changes in geometric and electronic parameters are observed upon interaction of ionic liquid electrolytes with C4N and CTF-0. The nature of interaction between ionic liquids and electrode surfaces is evaluated through Quantum theory of atoms in molecules (QTAIM) and non-covalent index (NCI) analyses which reveal that there exist only the non-covalent interactions (van der Waals) between them. Frontier molecular orbitals (FMO) analysis shows a significant decrease in energy gap upon interaction of ILs with CTF-0, which results in increase in electrical conductivity. Overall, porous CTF-0 electrode material displays greater interaction with the considered ILs as compared to non-porous C4N electrode material. This study will provide a way for experimentalist to explore ionic liquids and carbon nitride or covalent triazine framework as electrolyte–electrode systems which can be used further in energy storage devices like fuel cells, solar cells, ion batteries, and supercapacitors.