Experimental (FT-IR and FT-Raman) and theoretical (HF and DFT) investigation, IR intensity, Raman activity and frequency estimation analyses on 1-bromo-4-chlorobenzene

Spectroscopic, computational, cytotoxicity, and docking studies of 6-bromobenzimidazole as anti-breast cancer agent

6-Bromobenzimidazole (6BBZ) has been calculated in this study utilizing the 6-311++G(d,p) basis set and the Becke-3-Lee-Yang-Parr density functional approaches. The basic frequencies and geometric optimization are known. FTIR, FT-Raman, and UV-Vis spectra of the substance are compared between its computed and observed values. The energy gap between highest occupied molecular orbital-lowest unoccupied molecular orbital and molecule electrostatic potentials has been represented by charge density distributions that may be associated with the biological response. Time-dependent density functional theory calculations in the gas phase and dimethyl sulfoxide were carried out to ascertain the electronic properties and energy gap values using the same basis set. Molecular orbital contributions are investigated using the overlap population, partial, and total densities of states. Natural bond analysis was found to have strong electron delocalization by means of π(C4-C9) → π*(C5-C6), LP (N1) → π*(C7-C8), and LP(Br12) → π*(C5-C6) interactions. The Fukui function and Mulliken analysis have been explored on the atomic charges of the molecule. The nuclear magnetic resonance chemical shifts for 1 H and 13 C have been computed using the gauge-independent atomic orbital technique. With the highest binding affinity (-6.2 kcal mol-1 ) against estrogen sulfotransferase receptor (PDB ID: 1AQU) and low IC50 value of 17.23 μg/mL, 6BBZ demonstrated potent action against the MCF-7 breast cancer cell line. Studies on the antibacterial activity and ADMET prediction of the molecule have also been carried out.

Experimental and Theoretical Investigation of the Mechanism of the Reduction of O2 from Air to O22- by VIVO2+-N,N,N-Amidate Compounds and Their Potential Use in Fuel Cells

The two-electron reductive activation of O2 to O22- is of particular interest to the scientific community mainly due to the use of peroxides as green oxidants and in powerful fuel cells. Despite of the great importance of vanadium(IV) species to activate the two-electron reductive activation of O2, the mechanism is still unclear. Reaction of VIVO2+ species with the tridentate-planar N,N,N-carboxamide (ΗL) ligands in solution (CH3OH:H2O) under atmospheric O2, at room temperature, resulted in the quick formation of [VV(═O)(η2-O2)(κ3-L)(H2O)] and cis-[VV(═O)2(κ3-L)] compounds. Oxidation of the VIVO2+ complexes with the sterically hindered tridentate-planar N,N,N-carboxamide ligands by atmospheric O2 gave only cis-[VV(═O)2(κ3-L)] compounds. The mechanism of formation of [VV(═O)(η2-O2)(κ3-L)(H2O)] (I) and cis-[VV(═O)2(κ3-L)] (II) complexes vs time, from the interaction of [VIV(═O)(κ3-L)(Η2Ο)2]+ with atmospheric O2, was investigated with 51V, 1H NMR, UV-vis, cw-X-band EPR, and 18O2 labeling IR and resonance Raman spectroscopies revealing the formation of a stable intermediate (Id). EPR, MS, and theoretical calculations of the mechanism of the formation of I and II revealed a pathway, through a binuclear [VIV(═O)(κ3-L)(H2O)(η1,η1-O2)VIV(═O)(κ3-L)(H2O)]2+ intermediate. The results from cw-EPR, 1H NMR spectroscopies, cyclic voltammetry, and the reactivity of the complexes [VIV(═O)(κ3-L)(Η2Ο)2]+ toward O2 reduction fit better to an intermediate with a binuclear nature. Dynamic experiments in combination with computational calculations were undertaken to fully elucidate the mechanism of the O2 reduction to O22- by [VIV(═O)(κ3-L)(Η2Ο)2]+. The galvanic cell {Zn|VIII,VII||Id, [VIVO(κ3-L)(H2O)2]+|O2|C(s)} was manufactured, demonstrating the important applicability of this new chemistry to Zn|H2O2 fuel cells technology generating H2O2 in situ from the atmospheric O2.

Online measurement of 1,2,4-trichlorobenzene as dioxin indicator on multi-walled carbon nanotubes

Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) emission is one of main concerns for the secondary pollution of municipal solid waste incinerators (MSWI). For timely response to emission, 1,2,4-trichlorobenzene (1,2,4-TrClBz) as dioxin indicator can be monitored via online measurement techniques. In this study, multi-walled carbon nanotubes (MWCNTs) were investigated for their suitability as a 1,2,4-TrClBz sorbent for MSWI stack gas analysis. The tests include, batch adsorption, continuous adsorption-desorption of 1,2,4-TrClBz via thermal desorption coupled with gas chromatography (TD-GC-ECD), temperature and concentration stability of MWCNTs, and adsorption performance of the system. Thermogravimetric/derivative thermogravimetric (TGA/DTG) analysis reveals that MWCNTs has higher capacity in terms of weight loss (14.34%) to adsorb 1,2,4-TrClBz compared to Tenax TA (9.46%) and also shows fast desorption of adsorbate at temperature of 87 °C compared to Tenax TA (130 °C). Interestingly, carbon nanotubes and Tenax TA gave almost similar adsorption-desorption response, and from TD-GC-ECD analysis it was found that with increasing mass flow of 1,2,4-TrClBz (7.42 × 10^-6 - 44.52 × 10^-6 mg ml^-1) through sorbent traps, average peak areas increased from 2.86 ± 0.02 to 13.54 ± 0.26 for MWCNTs and 2.89 ± 0.02 to 13.38 ± 0.12 for Tenax TA, respectively. The stability of MWCNTs for temperature was 400 °C and for concentration of 1,2,4-TrClBz was 50 ppbv. However, regeneration of sorbent at 100 ppbv (1,2,4-TrClBz) was not possible. TD-GC-ECD system showed high adsorption performance with 3.86% and 3.59% relative standard deviation at 250 °C and 300 °C, respectively. Further Fourier Transform Infrared Spectroscopy (FTIR) analysis confirmed that adsorbate can be fully desorbed at 300 °C.

Synthesis, vibrational spectra, DFT calculations, Hirshfeld surface analysis and molecular docking study of 3-chloro-3-methyl-2,6-diphenylpiperidin-4-one

A newly synthesized molecular complex 3-chloro-3-methyl-2,6-diphenylpiperidin-4-one [CMDP] crystallizes in the triclinic space group P1. The piperidin-4-one ring exhibits a distorted chair conformation with the puckering parameters Q = 0.559 (3) Å, θ = 173.3 (3°) and φ = 180 (2°). The methyl substituent on the third position of the piperidine ring takes up a syn-periplanar positioning although the chloro substituent takes up an anti-clinical positioning with dihedral angle: Cl1-C2-C1-O1 = 113.3 (2°) due to the repulsion from an adjacent oxygen atom. The optimized molecular geometry and fundamental vibrational frequencies of the CMDP compounds are interpreted with the help of normal coordinate force field calculations based on DFT method B3LYP/6-31+G (d,p) level basis set. The HOMO-LUMO energy gap of the molecule is 5.4194 eV. The hardness value (η) of the CMDP molecule is 2.7097 eV. Hirshfeld surface analysis and fingerprint plots are supportive for determining the molecular shape and visually analyzing the intermolecular interactions in the crystal structure. The Hirshfeld surfaces like d_i,d_e,d_norm, shape index and curvedness of C₁₈H₁₈NOCl were pictured and discussed. The various levels of electronic transitions have been predicted by Time-Dependent Density Functional Theory (TD-DFT) calculations and compared with the recorded absorption spectrum. Molecular docking study was performed and reported for the synthesized compound against 4ey7 protein.

Quantum mechanical, spectroscopic and docking studies of 2-Amino-3-bromo-5-nitropyridine by Density Functional Method

Experimental and theoretical investigations on the molecular structure, electronic and vibrational characteristics of 2-Amino-3-bromo-5-nitropyridine are presented. The vibrational frequencies were obtained by DFT/B3LYP calculations employing 6-311++G (d, p) basis set. This was compared with experimental FT-IR and FT-Raman spectral data. Simulated FT-IR (4000-400cm^-1) and FT-Raman spectra (4000-100cm^-1) showed good agreement with the observed spectra. The molecular equilibrium geometry of the title compound was fully optimized. Quantum chemical calculations of the equilibrium geometry and the complete vibrational assignments of wavenumbers using potential energy distribution (PED) were calculated with scaled quantum mechanics. HOMO-LUMO energies, energy gap (ΔE), electronegativity (χ), chemical potential (μ), global hardness (η), softness (S) and the Fukui function were calculated for the title molecule. The title compound has a low softness value (0.239) and the calculated value of electrophilicity index (5.905) describes the biological activity. The stability and charge delocalization of the title molecule were studied by Natural Bond Orbital (NBO) analysis, Non-Linear Optical (NLO) behaviour in terms of first order hyperpolarizability, dipole moment and anisotropy of polarizability and Molecular Electrostatic Potential (MEP) were accounted. The computed values of μ, α and β for the title molecule are 1.851 Debye, 1.723×10^-23esu and 7.428×10^-30esu respectively. The high β value and non-zero value of μ indicate that the title compound might be a good candidate for NLO material. Thermodynamic properties of the title molecule were studied for different temperatures thereby revealing the correlations between heat capacity (C), entropy (S) and enthalpy changes (H) with temperatures. Docking studies of the title compound were scrutinized to predict the preferred binding orientation, affinity and activity of the given compound. The title compound was docked into the active site of the protein 5FCT which belongs to the class of proteins exhibiting the property as a Dihydrofolate synthase inhibitor. A minimum binding energy of -5.9kcal/mol and intermolecular energy of -6.5kcal/mol is seen in the interaction.

Effect of humic acid on the sulfamethazine adsorption by functionalized multi-walled carbon nanotubes in aqueous solution: mechanistic study

The presence of humic acid (HA) inhibited sulfamethazine (SMZ) adsorption by three types of multi-walled carbon nanotubesviacompetitive interactions, molecular sieving, and pore blockage in solution (pH < 9).

Adsorption of sulfamethazine by multi-walled carbon nanotubes: effects of aqueous solution chemistry

The adsorption of SMZ by MWCNTs was studied under varied pH, ionic strength, cations and anions in solution. The results indicated that hydrophobic and electrostatic interactions were the main adsorption mechanisms, and π–π interaction also played an important role.