Solvent-free mechanochemical synthesis, hirshfeld surface analysis, crystal structure, spectroscopic characterization and NBO analysis of Bis(ammonium) Bis((4-methoxyphenyl) phosphonodithioato)-nickel (II) dihydrate with DFT studies

Mechanochemical Synthesis of Chromium(III) Complexes Containing Bidentate PN and Tridentate P-NH-P and P-NH-P' Ligands

Chromium(III) complexes bearing bidentate {NH2(CH2)2PPh2: PN, (S,S)-[NH2(CHPh)2PPh2]: P'N} and tridentate [Ph2P(CH2)2N(H)(CH2)2PPh2: P-NH-P, (S,S)-(iPr)2PCH2CH2N(H)CH(Ph)CH(Ph)PPh2: P-NH-P'] ligands have been synthesized using a mechanochemical approach. The complexes {cis-[Cr(PN)Cl2]Cl (1), cis-[Cr(P'N)Cl2]Cl (2), mer-Cr(P-NH-P)Cl3 (3), and mer-Cr(P-NH-P')Cl3 (4)} were obtained in high yield (95-97%) via the grinding of the respective ligands andthe solid Cr(III) ion precursor [CrCl3(THF)3] with the aid of a pestle and mortar, followed by recrystallization in acetonitrile. The isolated complexes are high spin. A single-crystal X-ray diffraction study of 2 revealed a cationic chromium complex with two P'N ligands in a cis configuration with P' trans to P' with chloride as the counteranion. The X-ray study of 4 shows a neutral Cr(III) complex with the P-NH-P' ligand in a mer configuration. The difference in molecular structures and bulkiness of the ligands influence the electronic, magnetic, and electrochemical properties of the complexes as exhibited by the bathochromic shifts in the electronic absorption peaks of the complexes and the relative increase in the magnetic moment of 3 (4.19 μβ) and 4 (4.15 μβ) above the spin only value (3.88 μβ) for a d3 electronic configuration. Complexes 1-4 were found to be inactive in the hydrogenation of an aldimine [(E)-1-(4-fluorophenyl)-N-phenylmethanimine] under a variety of activating conditions. The addition of magnesium and trimethylsilyl chloride in THF did cause hydrogenation at room temperature, but this occurred even in the absence of the chromium complex. The hydrogen in the amine product came from the THF solvent in this novel reaction, as determined by deuterium incorporation into the product when deuterated THF was used.

Antimicrobial activity prediction, inter- and intramolecular charge transfer investigation, reactivity analysis and molecular docking studies of adenine derivatives

The utilization of the density functional theory (DFT) methodology has developed as a highly efficient method for investigating molecular structure and vibrational spectra, and it is increasingly being employed in various applications relating to biological systems. This study focuses on conducting investigations, both experimental and computed, to analyze the molecular structure, electronic properties and features of (E)-4-(((9H-purin-6-yl)imino)methyl)-2-methoxyphenol (ANVA). The expression ANVA should be rewritten as follows: the compound is a derivative of adenine (primary amine), specifically a vanillin (aldehyde). The present study reports the synthesis, characterization, DFT, docking and antimicrobial activity of ANVA. The optimization of the molecular structure was conducted, and the determination of its structural features was performed using DFT with the B3LYP/cc-pVDZ method. The vibrational assignments were determined in detail by analyzing the potential energy distribution. A strong correlation was observed between the spectra that were observed and the spectra that were calculated. The calculation of intramolecular charge transfer was performed using natural bond orbital analysis. In addition, several computational methods were employed, including highest occupied molecular orbital-least unoccupied molecular orbital analysis, molecular electrostatic potential calculations, non-linear optical, reduced density gradient, localization orbital locator and electron localization function analysis. This paper examines the present use of adenine derivatives in combatting bacterial and fungal infections, as well as the inclusion of spectral and quantum chemical calculations in the discussion.Communicated by Ramaswamy H. Sarma.

Photovoltaic properties of novel reactive azobenzoquinolines: experimental and theoretical investigations

In this work, synthesis, characterization, DFT, TD-DFT study of some novel reactive azobenzoquinoline dye structures to elucidate their photovoltaic properties. The azobenzoquinoline compounds were experimentally synthesized through a series of reaction routes starting from acenaphthene to obtained aminododecylnaphthalimide and finally coupled with diazonium salts to get the desired azobenzoquinoline. Azo dye synthesized differ in the number of alkyl chains designated as (AR1, AR2, AR3, and AR4) which were experimentally analyzed using FT-IR and NMR spectroscopic methods. The synthesized structures were modelled for computational investigation using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) combined with B3LYP and 6-31+G(d) basis set level of theory. The results showed that the HOMO-LUMO energy gap was steady at approximately 2.8 eV as the alkyl chain increases, which has been proven to be within the material energy gap limit for application in photovoltaic. The highest intramolecular natural bond orbital (NBO) for the studied compounds is 27.60, 55.06, 55.06, and 55.04 kcal/mol for AR1, AR2, AR3, and AR4 respectively and the donor and acceptor interacting orbitals for the highest stabilization energy (E (2)) are LP(1)N 18 and π*C 16−O 19 respectively. The photovoltaic properties in terms of light-harvesting efficiency (LHE), Short circuit current density (J SC), Gibbs free energy of injection (ΔG inj), open-circuit voltage (V OC) and Gibbs free energy of regeneration (ΔG reg) were evaluated to be within the required limit for DSSC design. Overall, the obtained theoretical photovoltaic results were compared with other experimental and computational findings, thus, are in excellent agreement for organic solar cell design.

Synthesis, characterization, and theoretical studies of the photovoltaic properties of novel reactive azonitrobenzaldehyde derivatives

All dyes conduct but at different degrees of absorption; it is interesting to study the degree of conductivity and absorptivity of novel reactive azo-dyes in respect to dye-sensitized solar cells (DSSCs) to ascertain their viability for such applications. In this study, four novel reactive azo-dyes were experimentally synthesized from p-aminobenzaldehyde, 4-amino-3-nitrobenzaldehyde, and aniline through series of condensation and coupling reactions. The various functional groups, molecular connectivities, and molecular weight of the various fragments of the synthesized dyes were elucidated using the GC-MS, FT-IR, UV-vis, and NMR respectively. The experimentally determined structures were modeled and investigated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) approaches to computationally compute the electronic structure properties, reactivity, absorption and solvatochromism in four different phases: gas, ethanol, acetone, and water, and the photovoltaic properties for possible applications in dye-sensitized solar cells (DSSCs). By comparing the HOMO (E_H) and the LUMO (E_L) energies from the results obtained demonstrates that dye D has the highest E_L energy value of −2.48 eV with a relatively lowest E_H energy value of −5.63 eV such that it lies underneath the conduction band edge of TiO₂ which is necessary to enable charge regeneration. Pi-electron delocalization was observed from the natural bond orbital (NBO) calculations between the different aromatic rings with dye B and A having the relatively highest and least second-order stabilization energies between σ* → σ* and LP* → LP interacting orbitals respectively. It is also observed in all the solvents that the Gibbs free energy of injection (ΔG_inject) is greater than 0.2 eV and hence, all the studied azo structures in the four phases provided efficient electron injection and light harvesting efficiency (LHE), however, the value of ΔG_inject for dyes B and D is greatest in all the four phases and thus, provided the highest electron injection of all the dyes. From the fact-findings of quantum theory of atoms-in-molecules (QTAIM), dyes A and C have extra-stability due to their relatively high numbers of intramolecular H-bond interactions along with some additional intra-atomic bonding between atoms within the studied compounds. Hence, all the four dyes are good for DSSCs applications.

Four novel reactive azo-dyes were experimentally synthesized from p-aminobenzaldehyde, 4-amino-3-nitrobenzaldehyde, and aniline through series of condensation and coupling reactions, and their properties were assessed for possible application in dye-sensitized solar cells.

Investigation on electronic structure, vibrational spectra, NBO analysis, and molecular docking studies of aflatoxins and selected emerging mycotoxins against wild-type androgen receptor

The geometry, frontier molecular orbitals (FMOs), vibrational, NBO analysis, and molecular docking simulations of aflatoxins (B1, B2, M1, M2, G1, G2), zearalenone (ZEA) emodin (EMO), alternariol (AOH), alternariol monoethyl ether (AMME), and tenuazonic acid (TeA) mycotoxins have been extensively theoretically studied and discussed based on quantum density functional theory calculations using Gaussian 16 software package. The theoretical computation for the geometry optimization, NBOs, and the molecular docking interaction was conducted using Density Functional Theory with B3LYP/6-31+G(d,p), NBO program, and AutoDock Vina tools respectively. Charge delocalization patterns and second-order perturbation energies of the most interacting natural bond orbitals (NBOs) of these mycotoxins have also been computed and predicted. Interestingly, among the mycotoxins investigated, aflatoxin G1 is seen to give the strongest stabilization energy while Zearalenone shows the highest tendency to accept electron(s) and emodin, an emerging mycotoxin gave the best binding pose within the androgen receptor pocket with a mean binding affinity of -7.40 kcal/mol.

Intermolecular hydrogen bond interactions in the thiourea/water complexes (Thio-(H2O)n) (n = 1, …, 5): X-ray, DFT, NBO, AIM, and RDG analyses

This study aims to experimentally and theoretically examine the nature and energy of intermolecular bond interactions between thiourea and water molecules using natural bond orbital (NBO), non-linear optical (NLO), atoms in molecules (AIM), and reduced density gradient (RDG) analyses based on the quantum chemical approach and spectroscopic analysis on X-ray and FTIR. Geometry optimizations of Thio-(H₂O)_1-5 complexes were carried out in the gas phase by B3LYP/6-311++G(d,p) level of density functional theory. The nature of the molecular interactions between the water and thiourea through hydrogen bonding has been investigated using RDG and AIM methods. NBO analysis shows that the Thio-(H₂O)₅ complex has higher stabilization energy values than the other complexes. The non-linear optical properties, such as dipole moment (μ), the polarizability (α₀), and the first hyperpolarizability (β_tot), and thermodynamic functions, such as entropy (S), specific heat capacity (C_v), and thermal energy (E), were calculated using the same method. It was observed that thermodynamic parameters, polarizability, and the first hyperpolarizability increased with the number of water molecules. X-ray diffraction analysis confirmed that thiourea is single crystal, and the thiourea/water complexes are crystalline in nature. Besides, the infrared spectrum shows the existence of water molecules and it is used to get details of the structure of the complex.