Frontier Molecular Orbital Analysis Research Articles

Design, synthesis, and characterization of a novel pH-responsive azo dye incorporating a 1,3,4-thiadiazole ring for advanced textile applications

This study presents the synthesis and comprehensive characterization of a novel azo dye derived from 2-(5-amino-1,3,4-thiadiazol-2-yl) phenol (1a). The synthesis was initiated by reacting salicylic acid with thiosemicarbazide in the presence of phosphorus oxychloride (POCl3), yielding an 89 % conversion to compound 1a. The subsequent diazotization and coupling of 1a under alkaline conditions led to the formation of the azo dye (1b). Structural elucidation was confirmed through Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The incorporation of the 1,3,4-thiadiazole ring is significant due to its known influence on enhancing dye stability, reactivity, and potential biological activities, while the salicylic acid moiety contributes to the dye's pH responsiveness. A notable pH-dependent color transition from yellow (pH < 6.0) to red (pH > 8.0) was observed, driven by protonation-induced resonance changes. Computational studies, including Frontier Molecular Orbital (FMO) analysis, revealed a Highest Occupied Molecular Orbital (HOMO)-Lowest Unoccupied Molecular Orbital (LUMO) gap of 1.94 eV, indicating efficient electronic transitions critical for its color properties. Molecular Electrostatic Potential (MEP) and Fukui function analyses provided further insights into the dye's reactivity and potential applications. The dyeing properties were rigorously assessed through K/S values, CIELAB color space, and fastness properties on cotton fabric, demonstrating varied color depths and hues influenced by different mordants, with copper and manganese significantly enhancing color intensity. Colorfastness tests revealed good to fair durability, with untreated fabrics showing optimal performance. This thorough characterization underscores the promising potential of this newly synthesized azo dye for applications in pH-responsive textiles and functional materials, highlighting its relevance for advanced textile and material science applications.

Research on the molecular structure, solvent effects, quantum computing, topology, and biological aspects of 4-phenylcoumarin-7-yl-methacrylate as an anticancer agent

The objective of this research is to conduct both experimental and theoretical analyses on the synthesis and characterization of a new coumarin derivative known as 4-phenylcoumarin-7-yl-methacrylate (PCMA). To accomplish this, several methods including 1H-NMR, FT-IR, and UV-visible spectroscopy were employed, and atomic charges and bond parameters were calculated using the DFT-B3LYP/6-311G++(d,p) basis set. Additionally, topological properties such as Electron Localized Function, Localized Orbital Locator and Non-Covalent interactions (RDG-NCI) were thoroughly examined. The TD-DFT approach was used to calculate the UV-Vis absorption technique in various solvent media, and the Light Harvesting Efficiency was also investigated. An analysis of Frontier Molecular Orbitals (FMO), Molecular Electrostatic Potential (MEP), and Average Local Ionization Energy (ALIE) simulations were conducted to identify the optimal sites for both electrophilic and nucleophilic attacks. Nonlinear Optical (NLO) behavior was also examined by determining the dipole moment (μ), the linear polarizability (α), first hyperpolarizability (β) and second hyperpolarizability (γ) through the use of the same basis set. To better understand molecular stability and interactions, Natural Bond Orbital (NBO) analysis was performed, providing insights into hyperconjugative interactions, charge delocalization, and electron density (ED) among the molecular components. Electron-hole and TDM analysis were also conducted to investigate the various types of electron-excited states. This research will additionally explore the drug-likeness and docking potential of PCMA, with the goal of determining its suitability as a potential candidate for cancer treatment. This comprehensive study offers valuable insights into the structural, electronic, and biological properties of 4-phenylcoumarin-7-yl-methacrylate (PCMA).

Computational analysis of C9N4 monolayer as a novel adsorbent for toxic gases

A novel C9N4 nanosheet has been investigated for its potential use as an electrochemical sensor for gaseous pollutants including CO, NO, CO2, HF, and COCl2. The sensing ability of C9N4 is explored theoretically at the ωB97XD/6-311G (d, p) level of theory. The results showed the physisorption of all analytes on the C9N4 surface. The highest interaction energy of −21.96 kcal/mol was observed in COCl2@C9N4. The order of interaction energy was COCl2@C9N4> NO@C9N4 > HF@C9N4 > CO2@C9N4 > CO@C9N4. The Electronic properties of the complexes were examined using EDD (Electron Density Difference), NBO (natural bond orbital), FMO (frontier molecular orbital), and DOS (density of state) analysis. According to NBO analysis, CO2@C9N4 exhibited the maximum amount of charge transfer (−0.026 e−), whereas COCl2@C9N4 exhibited the minimum amount of charge transfer. The adsorption of COCl2 onto the surface of C9N4 resulted in change in the energy gap with a value of −3.12 eV compared to −3.15 eV for C9N4. These findings highlighted the potential of C9N4 as a promising electrochemical sensor for COCl2. The transfer of charges takes place from the analytes to the C9N4, except in HF, where no charge transfer took place. This divergence could be attributed to the strongly bonded electrons between the fluorine and hydrogen atoms of HF. QTAIM and NCI analysis were performed to determine the nature of non-covalent interactions. At 298K, a recovery time of 1.25 × 104 s was calculated for the desorption of COCl2 from the surfaces of C9N4. It was observed that C9N4 shows the highest sensitivity toward COCl2 among all selected analytes.

Investigations of fluorescence emission Mechanism: Formation of ring-like structures by interactions influenced by hydroxyl group and deprotonation

As one of the gaseous signaling molecules in biological systems, hydrogen sulfide(H2S) is involved in numerous physiological processes and diseases. Therefore, rapid, effective, and real-time detection of H2S is of great importance. Based on its excellent optical properties, dicyanoisophorone has attracted much attention in recent years, and a large number of corresponding probes have been developed to detect H2S in biological systems. In this paper, the fluorescence mechanisms of three dicyanoisophorone-based fluorescent probes are investigated and the near-infrared (NIR) fluorescence attribution of the products is discussed by density-functional theory and time-dependent density-functional theory methods. Frontier molecular orbital analysis shows that the non-fluorescence of the probes is attributed to the photo-induced electron transfer process. Structural change and reduced density gradient analyses indicate that the position of the hydroxyl group and the deprotonation have a non-negligible influence on the interactions within the products. The five- or six-membered ring-like structures formed by interactions make the molecule stain as a planar and the fluorescence emission, while the twist exists the fluorescence quenching. In addition, spectral information shows that the emission of NIR fluorescence originates from the deprotonated form of the product.

DFT studies on the performance of BN nanocage (B12N12) as adsorbent and sensor for fosfomycin

The investigation focused on exploring the potential applications of the BN nanocage (B12N12) as both an adsorbent and a sensor for removing and detecting fosfomycin (FM) using density functional theory computations. In this respect, the interaction of FM with B12N12 was evaluated at 3 different configurations and the most stable one was determined. The results showcased the interaction between FM and B12N12, highlighting the feasibility, exothermic nature, and spontaneity of the interaction, emphasizing the effectiveness of B12N12 as an FM adsorbent. Moreover, the study scrutinized the influence of water as a solvent and different temperatures on the thermodynamic parameters. Interestingly, the results indicated that these factors had negligible impacts on the interactions. Nonetheless, it was noted that the interactions were a bit stronger in vacuum and at lower temperatures. Additionally, the Frontier Molecular Orbital (FMO) analysis exhibited a bandgap of 6.716 eV for B12N12, which increased by approximately 90 % to 13.381 eV upon FM adsorption, indicating a significant reduction in the electrochemical conductivity of BN nanocage during the FM adsorption process, thereby hinting at its potential use as an analytical signal for the electrochemical detection of FM.

A new combined collector of sodium oleate and 1,12-dodecanediamine for efficient flotation separation of spodumene from feldspar

A new combined collector of NaOL and 1,12-Dodecanediamine (DA122) was used for efficient flotation of spodumene from feldspar. The disparities in mineral flotation efficacy between the combined collectors of NaOL/1,12-Dodecanediamine and NaOL/Dodecylamine (DDA), as well as the underlying mechanisms, were comprehensively analyzed by the measurements of flotation experiments, surface tension, adsorption amount measurement, structure and frontier molecular orbital analysis and adsorption model calculation. The results of mixed minerals micro-flotation indicate that the Li2O recovery of 91.64 % was achieved using NaOL and DA122 combined collector, which represents an 11.54 % increase in Li2O recovery compared to using the NaOL and DDA combined collector. NaOL and DA122 combined collector exhibits a lower critical micelle concentration (CMC) and the greater adsorption amount on the surface of spodumene. NaOL and DA122 combined collector demonstrates higher reactivity and adsorption energy on the surface of spodumene, resulting in higher hydrophobicity of spodumene because DA122 possesses stronger ability to lose electrons than DDA, thus leading to higher recovery of spodumene.

Computational Investigations on Bis‐(ferrocenylmethyl)‐Based Sulphur Rich Sensitizers for Dye‐Sensitized Solar Cells

AbstractIn this work, a computational investigation of ferrocene (Fc)‐based compounds FcCH2CS3CH2Fc (1) and FcCH2SSCH2Fc (2) sensitizer for dye‐sensitized solar cells (DSSCs) has been carried out to comprehend the photophysical and photo‐electrochemical properties. The density functional theory (DFT) and time‐dependent DFT (TD‐DFT) were employed to assess the photovoltaic parameters of the compounds. The frontier molecular orbital analysis revealed the electron density distribution at HOMO and LUMO, which clearly demonstrates the charge separation within the compounds. The electronic absorption spectra are simulated using the TD‐DFT method to comprehend the ability of the compounds to harvest sunlight and efficiently act as photosensitizer. Simulation of electronic spectra of dye@TiO2 cluster exhibits that the absorption coefficient of compound 1 is higher than compound 2 due to the greater extent of charge transfer from the dye to the TiO2 cluster. These computational findings are corroborated by the reported photovoltaic performance of the compounds.

Molecular Interactions Between Hexanal Schiff Bases and Boron Nanocages: A DFT Approach

This study explores the interactions between hexanal Schiff bases and a B12N12 nanocage, employing density functional theory (DFT) calculations to deepen our understanding of noncovalent bonds. Hexanal, a key component in tea, plays a vital role in prolonging the shelf-life of various plant-based products by inhibiting phospholipase-D. Our research initially focused on synthesizing Schiff bases through the condensation of hexanal with nucleobases and an amino acid. We then conducted a series of DFT calculations, including geometry optimizations, frontier molecular orbital (FMO), natural bond orbital (NBO) and noncovalent interactions (NCI) assays, using Gaussian 16 and ORCA 5.0.2 software packages. This study reveals that hexanal Schiff bases form stable complexes with the B12N12 nanocage, exhibiting notable dative coordinate bonding. The FMO analysis indicates a significant energy gap variation among the complexes, with CSB2 showing the lowest energy gap, hinting at its high reactivity. In the LED assay, CSB2 demonstrates the lowest decomposition energy, highlighting its potential stability. The AIMD simulations provide insights into the electronic motions of these complexes, underscoring their dynamic nature. Our NBO analysis offers a comprehensive view of the electron distribution within these complexes, emphasizing the significance of nitrogen and boron atoms in the bonding process. The NCI assay sheds light on the predominant van der Waals and steric interactions contributing to the stability of the complexes. This investigation provides a detailed account of the NCI between hexanal Schiff bases and the B12N12 nanocage. The findings not only contribute to the field of noncovalent bonding in inorganic-fullerene structures but also open avenues for future applications in material science and molecular engineering.

Sunlight-activated dye degradation of ZnO/CdO-decorated graphene oxide and its antibacterial activity

The pollution of water sources by hazardous substances such as sulfates, cyanides, and heavy metals represents a major environmental challenge. Addressing these issues requires the degradation of pollutants in wastewater to mitigate our environmental crises. Graphene oxide (GO) significantly enhances the mechanical and functional properties of GO-ZnO and GO-CdO nanocomposites, making them promising materials for applications in both sensors and catalysts. In this context, two optically active metal oxide-decorated graphene oxides (GO-ZnO and GO-CdO) were synthesized, and their photocatalytic efficacy against methylene blue (MB) was evaluated. Using an FT-IR spectrophotometer, the vibrational modes of hydroxyl (OH), carbonyl (C]O), and carboxylic (COOH) groups were identified. Raman spectroscopy analysis provided additional insights, confirming these vibrational properties. These materials exhibited peak photon absorption (λmax) at 242 nm and an optical band gap of 3.7 eV. Frontier molecular orbital (FMO) analyses indicated significant electronic charge transfer on the materials' surfaces, demonstrating their excellent capacity for adsorbing MB. An optimal catalyst dosage of 50 mg was found to be most effective in accelerating the degradation of MB. Additionally, variations in the initial pH of the solution showed a direct correlation, with higher pH levels leading to enhanced degradation efficiency, reaching up to 97 % after 120 min. Quantum Theory of Atoms in Molecules (QTAIM) analyses revealed that MB is extensively adsorbed and degraded through a series of hydrogen bonding interactions. Moreover, experimental results indicate that both materials have a significant impact on bacterial destruction, suggesting their potential as novel antibacterial agents.

Synthesis, structural analysis, and molecular docking of a novel 1,3,4-thiadiazole derivative: An experimental and molecular modeling studies

This study reports on the synthesis and characterization of a new thiadiazole derivative, (E)-N-(5-(2-nitrostyryl) -4-acetyl -4,5-dihydro -1,3,4-thiadiazol -2-yl) -N-phenylacetamide (ETDZ). The crystal structure was determined by single-crystal X-ray diffraction. ETDZ belongs to the monoclinic I2/a space group. The contribution of intermolecular interactions was assessed by Hirshfeld surface analysis and fingerprint plots. FT-IR, UV–Vis, and NMR (1H and 13C) techniques were used for spectroscopic characterization. The 1H and 13C NMR spectra were recorded in CDCl3 solvent. Density functional theory, employing the B3LYP functional and 6–311G(d,p) basis set in chloroform solvent, was used to calculate the structural and spectroscopic parameters of the molecule in the ground state. The vibrational wavenumbers were calculated and compared with the experimental FT-IR spectrum using the scaled quantum mechanics method. Isotropic chemical shifts were calculated using the Gauge invariant atomic orbital method. The calculated NMR chemical shifts and absorption wavelengths were compared with the experimental values, indicating good results from the DFT and TD-DFT methods. To get more information about charge transfer within the molecule, electronic properties such as HOMO and LUMO energies were studied using the DFT approach. The molecular electrostatic potential, frontier molecular orbital analysis, energy band gap, density of state, global chemical reactivity descriptors, and some thermodynamic functions were also calculated. Reduced density gradient and atom-in-molecule analysis were performed to investigate inter- and intra-non-covalent interactions. Molecular docking was carried out with the Eg5 kinesin protein, confirming the biological assets of the ETDZ ligand as a mitochondria disease and cancer agent.

Remarkable enhancement of the nonlinear optical behavior towards asymmetric substituted D-π-A dithiophene-based compounds.

Nonlinear optics (NLO) is an interesting field that discloses the interaction between intense light and matter, leading to a deeper understanding of NLO phenomena. Organic chromophores are considered as promising materials for NLO due to their exceptional structural versatility, ease of processing, and rapid response to NLO effects. Functional materials based on thiophene have been indispensable in advancing organic optoelectronics. Specifically, dithiophene-based compounds display weaker aromaticity, reduced steric hindrance, and additional sulfur-sulfur interactions. Hence, by utilizing dithieno[2,3-d:2',3'-d']benzo[1,2-b:4,5-b']dithiophene (DTBDT) as the core structure, designing of a set of organic compounds with D1-π-D2-π-A-type framework, namely ZR1D1-ZR1D8, was carried out in this study. The analysis of frontier molecular orbitals (FMOs) revealed that compound ZR1D2 has the lowest band gap of 1.922eV among all the investigated chromophores. The correlation of global reactivity parameters (GRPs) with the band gap values indicates that ZR1D2 displays a hardness of 0.961eV and a softness of 0.520eV-1. Among the studied compounds, ZR1D2 demonstrated a broad absorption spectrum that extended across the visible region. The maximum absorption wavelengths were observed at 766.470nm for ZR1D2 and 749.783nm for ZR1D5. These DTBDT-based dyes exhibit a remarkable NLO response with exceptionally high first hyperpolarizability (βtot) values. Among them, compound ZR1D2 stands out with the highest average linear polarizability (⟨α⟩ = 3.0 × 10-22 esu), first hyperpolarizability (βtot = 4.1 × 10-27 esu), and second hyperpolarizability (γtot = 7.5 × 10-32 esu) values. In summary, this investigation offers valuable insights into the potential use of DTBDT-based organic chromophores, particularly ZR1D2, for advanced applications in NLO. These findings suggest promising opportunities for researchers to synthesize these molecules and utilize these compounds in hi-tech NLO-based applications. The density functional theory computations were performed at the M06/6-311G(d,p) functional to explore their structural effects on electronic and NLO findings. Various analyses like highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps, absorption maxima, density of states, open circuit voltage, binding energies of electrons and holes, and transition density matrix are employed to investigate photovoltaic efficiencies of the derivatives. Different software packages like Avogadro, Multiwfn, Origin, GaussSum, PyMOlyze, and Chemcraft were used to deduce conclusions from the output files.

Unveiling spectroscopic behaviour and molecular features (DFT studies) of Exemestane-maleic acid cocrystal as model multicomponent system

The present study aimed to investigate the Exemestane - maleic acid (Ex-Mal) cocrystal using Fourier-transform Raman (FT-Raman), Fourier-transform Infrared (FT-IR), Powder X-ray Diffraction (PXRD) and Differential Scanning Calorimeter (DSC) experimental techniques and quantum chemical calculations. Exemestane (Ex) is an irreversible aromatase inhibitor, clinically used for the treatment of postmenopausal women having primary or advanced breast cancer. Maleic acid (Mal), a dicarboxylic acid is found in many vegetables and fruits and is used as a food additive and sweetener. Solution crystallization of Ex and Mal was done in the generation of Ex-Mal cocrystal (1:1). PXRD and DSC analysis confirmed the successful generation of Ex-Mal Cocrystal. Intermolecular hydrogen bonding (O4-H12···O13 & C8-O3···H36) also suggested the formation of a multi-component system, Ex-Mal cocrystal (1:1), as the respective modes shifted in the vibrational (Raman & IR) spectra of cocrystal than the Ex. Further, the quantum theory of atoms in molecules (QTAIM) has been done to analyze the strength and nature of inter-/intra molecular hydrogen bonding. Natural bond orbital (NBO) analysis was performed to check the stabilization energy of the system. The frontier molecular orbital (FMO) analysis predicted that Ex-Mal cocrystal is more reactive and less stable than Ex. Molecular electrostatic potential (MEP) surface showed that electrophilic (C16-H36)/(O4-H12), and nucleophilic (C8=O3)/(C17=O13) reactive groups in Ex/Mal and Mal/Ex, respectively, neutralized after the formation of Ex-Mal cocrystal, confirming the presence of hydrogen bonding interactions (C16-H36∙∙∙O3=C8) and (C17=O13∙∙∙H12-O4). Molar Refractivity (MR) was calculated to check the drug-likeness behaviours of Ex-mal cocrystal. This study provided a comparison of experimental and theoretical results to understand the hydrogen bonding interactions and structural activity of the system.

Mechanism of bioactive 3,3′-diindolylmethane formation in flaxseed meal-xylose-tryptophan maillard reaction

3,3′-Diindolylmethane (DIM) has attracted extensive attention due to its bioactivity, and is applied to the fields of food, medicine and so on. In the study, DIM was isolated from the flaxseed meal-xylose-tryptophan Maillard reaction products. Its formation mechanism was investigated using the isotope labeling method. The reactive sites in DIM were analyzed by quantum chemistry calculation. The results showed that the Maillard reaction of tryptophan and xylose produced indole-3-formaldehyde, which further reacted to generate indole-3-methanol. Indole-3-methanol was unstable and eventually formed DIM. The molecular structure of DIM was determined and then the best configuration was obtained by frequency calculation. The molecular potential energy and frontier molecular orbital analysis showed that the main action site in DIM was near the indole ring. This study may provide a theoretical basis for in-depth studies on the relationship between the molecular structure and properties of DIM, broaden its applications in food, and offer a reference for the rational development of functional foods.

A rational design of metal doped C20 fullerene based sensor for the selective detection of ethyl butyrate as COVID-19 biomarker

The detection of ethyl butyrate as a COVID-19 biomarker in exhaled breath could be a novel, rapid, less expensive, painless and non-invasive technique compared to a costly, painful and time-consuming PCR test. The potential of alkaline earth metals doped C20 fullerenes (M@C20) was explored as sensing materials to detect ethyl butyrate selectively. The ethyl butyrate (EB) exhibited the physisorption on pristine C20 fullerene with adsorption energy of -4.16 kcal/mol, while chemisorption was observed with M@C20 fullerenes. The frontier molecular orbital analysis demonstrates enhanced stability of complexes, attributed to widened Eg gaps during EB adsorption onto M@C20 fullerenes. The notable shift in λmax values in the visible region suggests using M@C20 fullerenes as UV–visible-based naked-eye sensors. The infrared analysis showed a red shift in the carbonyl bond stretching frequency of ethyl butyrate upon adsorption onto M@C20 fullerenes. The red shift resulted from charge transfer from ethyl butyrate to M@C20. These findings establish the foundation for utilizing M@C20 fullerenes in IR-based handheld sensing devices. The minimum recovery time (6.8 s) demonstrates Ca@C20 fullerene as a promising, reusable sensor for detecting ethyl butyrate at human body temperature. Our results pave the way to design rapid, reusable sensors for detecting ethyl butyrate.

Theoretical evaluation of C24 nanocage functionalization with protons for enhanced sulfacetamide drug delivery: A DFT study with non-covalent interaction analyses

In the realm of drug design, achieving precise and effective drug delivery poses a significant challenge. In this computational study, we explore the capacity of pristine C24 nanocages and those modified with 1H+ and 2H+ ions to serve as carriers for the sulfacetamide (SA) drug, employing density functional theory (DFT) calculations. Geometry optimizations of the SA&C24, SA&H+C24, and SA&2H+C24 complexes were conducted at the cam-B3LYP/6–31+G (d, p) level of theory. The optimized structures of all complexes exhibit local minima on the potential energy surface, indicated by the absence of imaginary frequencies, which confirms their thermodynamic stability. The negative values of adsorption energy (Eads) denote an exothermic and favorable adsorption process, with H+ ion functionalization enhancing the drug's binding affinity to the nanocages. Further analysis of the structural properties of the complexes was conducted through natural bond orbital (NBO) charge distribution, dipole moment calculations, and frontier molecular orbital analysis. Additionally, Atoms in Molecules (AIM), reduced density gradient (RDG), and electron localization function (ELF) analyses were employed to elucidate the nature of intermolecular interactions governing the drug-nanocage binding. UV-visible and nonlinear optical (NLO) response calculations reveal the potential of both pristine and functionalized C24 nanocages as optical sensors for SA drug detection. Our findings suggest that these nanocages hold promise for the development of sensitive drug delivery vehicles and targeted therapeutic agents.

Crystallographic analysis, Hirshfeld surface investigation, and DFT calculations of 2-phenoxy-triazoloquinazoline molecule: Implications for drug design

This study presents a comprehensive structural and computational investigation of 2-phenoxy-1,2,4-triazolo[1,5-a]quinazoline (PTQ), a compound with promising pharmacological potential. Single-crystal X-ray diffraction (SCXRD) analysis revealed the molecular geometry and crystal packing, while density functional theory (DFT) calculations provided insights into electronic properties and reactivity. Hirshfeld surface analysis elucidated intermolecular interactions, highlighting hydrogen bonding, van der Waals forces, and π–π stacking as crucial factors in crystal stability. Fingerprint analysis quantified these interactions, revealing the dominance of hydrogen contacts and the significance of hydrogen bonds and C–H···π interactions. Void analysis identified potential areas for inclusion complex formation. Frontier molecular orbital analysis and molecular electrostatic potential (MEP) mapping identified potential electrophilic and nucleophilic sites, guiding future reactivity studies. Furthermore, in silico ADMET and molecular docking studies were performed to assess the drug-likeness and potential antihistamine activity of PTQ.

Exploration of supramolecular interactions, Hirshfeld surface, FMO, molecular electrostatic potential (MEP) analyses of pyrazole based Zn(II) complex

The supramolecular interactions of title compound [Zn(HL2)](ClO4)2(MeOH)2] (1) where, HL2=((Z)-N’-(5-methyl-1H-pyrazole-3-carbonyl)pyrazine-2-carbohydrazonamide) are explored in detail. With a detailed scrutiny of visualizing of title compound 1, the crystal packing is mainly directed by strong hydrogen bonding interactions observed N–H⋯N and N–H⋯O but, in addition, weak interactions such as C–H⋯π, π⋯π are also sighted to stabilize the crystal self-assembly. Electronic structure of the complex is determined using DFT calculations at B3LYP level with mixed basis set. Theoretically calculated structural parameters are in good match with the experimentally obtained parameters from XRD. TDDFT calculation is performed to simulate the UV–Vis absorption spectra of the complex. Molecular reactivity and stability of the complex has been assessed through frontier molecular orbital analysis and also through evaluation of molecular electrostatic potential (MEP). Hirshfeld surface analysis, which uses molecular surface contours and 2D fingerprint plots to visually analyze intermolecular interactions in crystal structures, has been used to examine molecular morphologies. The Hirshfeld surface and fingerprint plots are accompanied by crystal structure analysis allowed for the discovery of the important intermolecular interactions.

Study of electronic structure of organic solar cell molecules

This study employs the 6-311G(2d,2p) basis set and the B3LYP functional within the density functional theory (DFT) framework,using Gaussian09 suite, to examine the electronic proper- ties of experimental molecules, including Benzo[1,2-b:5,5 b’]dithiophene, 2-2’bithiophene, and 3,4 ethylenedioxythiophene, crucial components of organic solar cells. The geometrical structures of these molecules are depicted, highlighting their individual components. Frontier Molecular Orbitals (FMOs) analysis reveals the significance of the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) in the electrical structure of molecules, impacting various quantum chemical parameters and predicting reactivity, stability, and solar cell efficiency. Molecular absorption coefficients, UV-visible spectroscopy data, and molecular electrostatic potential (MESP) maps further elucidate the light absorption, stability, and reactivity of these molecules. The results suggest that 2-2’bithiophene exhibits superior electron-donating capacity and nucleophilicity, while 3,4 ethylenedioxythiophene displays heightened electrophilicity. Benzo[1,2-b:5,5 b’]dithiophene shows greater light absorption capability and light-harvesting potential. Understanding these elec- tronic properties aids in optimizing the efficiency of organic photovoltaic cells.

Hydration effects on molecular structure, vibrational, electronic properties, drug-likeness analysis, molecular docking, and molecular dynamics studies of (Z)-3-(2-oxo-2-phenylethylidene)indolin-2-one

This study examines how solvation models, including COSMO, CPCM, PCM, and SMD, affect the conformations, molecular structure, vibrational behaviors, and electronic properties of the (Z)-3-(2-oxo-2-phenylethylidene)indolin-2-one (Z3-2O2PEI) molecule within the framework of the B3LYP/cc-pVTZ model chemistry, along with its potential effectiveness as a drug for treating COVID-19. The most stable molecular conformation of the studied coùpound was identified in the presence of the COSMO solvent. The theoretical vibrational frequencies matched the experimentally observed FT-IR and Raman data. Solvent influences on the UV–vis spectra of Z3-2O2PEI revealed electronic transitions from n to π* and π to π* orbitals, along with evidence of intermolecular charge transfer (ICT) supported by analyses of Frontier Molecular Orbitals (FMO) and Natural Bond Orbitals (NBO). The examinations of Mulliken atomic charge distributions and molecular electrostatic potential surfaces reveal the electrophilic and nucleophilic sites of the molecule under study. Non-covalent Interaction (NCI) analysis confirmed the presence of steric effects and Van der Waals interactions within the compound. According to molecular docking studies, the Z3-2O2PEI molecule exhibits significant binding affinity for PLpro, a protein targeted in COVID-19 treatment. This finding is supported by subsequent molecular dynamics analysis, validating the docking results.

Pyrimidine-based sulfonamides and acetamides as potent antimicrobial Agents: Synthesis, Computational Studies, and biological assessment

A series of novel sulfonamide and acetamide derivatives of pyrimidine were synthesized and their antimicrobial activities were assessed. Based on the Microbroth dilution method, the minimum inhibitory concentration (MIC) of the synthesized compounds demonstrated moderate to good levels of antifungal and antibacterial activity. Structure-activity relationship analysis suggested that the presence of electron-withdrawing groups, such as halogens, nitrile, and nitro groups, on the pyrimidine ring contributed to the enhanced antimicrobial potency, while electron-donating substituents led to a decrease in activity. Computational studies, including density functional theory (DFT), frontier molecular orbitals (FMO), and molecular electrostatic potential (MEP) analysis, provided insights into the electronic properties and charge distribution of the compounds. Drug-likeness evaluation using ADME/Tox analysis indicated that the synthesized compounds possess favorable physicochemical properties and could be potential drug candidates. Molecular docking against the Mycobacterium TB protein tyrosine phosphatase B (MtbPtpB) revealed that the synthesized compounds exhibited strong binding affinities (−46 kcal/mol to − 61 kcal/mol) and formed stable protein–ligand complexes through hydrogen bonding and π-π stacking interactions with key residues in the active site. The observed interactions from the docking simulations were consistent with the predicted interaction sites identified in the FMO and MEP analyses. These findings suggest that the synthesized pyrimidine derivatives could serve as promising antimicrobial agents and warrant further investigation for drug development.