Vibrational Assignments Research Articles

The radiative efficiency and global warming potential of HCFC-132b.

Hydro-chloro-fluoro-carbons (HCFCs) are potent greenhouse gases which strongly absorb the infrared (IR) radiation within the 8 - 12 μm atmospheric windows. Despite international policies schedule their phasing out by 2020 for developed countries and 2030 globally, HCFC-132b (CH2ClCClF2) has been recently detected with significant atmospheric concentration. In this scenario, detailed climate metrics are of paramount importance for understanding the capacity of anthropogenic pollutants to contribute to global warming. In this work, the radiative efficiency (RE) of HCFC-132b is experimentally measured for the first time and used to determine its global warming potential (GWP) over 20-, 100- and 500-year time horizon. Vibrational- and rotational-spectroscopic properties of this molecule are first characterized by exploiting a synergism between Fourier-transform IR (FTIR) spectroscopy experiments and quantum chemical calculations. Equilibrium geometry, rotational parameters and vibrational properties predicted theoretically beyond the double-harmonic approximation, are employed to assist the vibrational assignment of the experimental trace. Finally, FTIR spectra measured over a range of pressures are used to determine HCFC-132b absorption cross section spectrum from 150 to 3000 cm-1, from which istantaneous and effective REs are derived and, in turn, used for GWP evaluation.

An experimental insight into a promising novel organic nonlinear optical single crystal Guanidinium 2,4-dichlorobenzoate (G24DCB)

Guanidinium 2,4-dichlorobenzoate (G24DCB), a new chloro substituted benzoic acid based organic single crystal is synthesized, grown and added to the guanidinium family of single crystals. Such G24DCB crystal was obtained by a versatile slow evaporation solution growth technique. The analysis of single crystal X-ray diffraction examined the phase identification and determination of lattice parameters for the synthesized compound. The G24DCB crystal has monoclinic system and adopts space group P21/c. Powder X-ray diffraction explores the studied crystal's crystalline characteristics. The study of Fourier Transform-Infrared (FTIR) spectroscopy examined the necessary vibrational assignments for the formation of the structure of G24DCB. The UV–Visible-NIR analysis entails the determination of the cut-off wavelength of the G24DCB compound from its transmittance spectrum and the computation of other related optical parameter values. Photoluminescence analysis was employed to investigate the studied crystal's emission characteristics. The thermal stability of the G24DCB crystal was examined through thermogravimetric analysis and differential thermal analysis. The laser-induced damage threshold of the crystal was determined using a Nd:YAG laser. The various mechanical attributes exhibited by the synthesized compound were elucidated by microhardness studies and it corresponds to a soft material type. The various third order nonlinear optical characteristics were probed by Z scan study. The positive results of the aforementioned studies suggest the emerging significance possessed by the novel title crystal Guanidinium 2,4-dichlorobenzoate in nonlinear optical applications.

Anatase TiO2 Surface Hydration: Infrared Vibrational Assignment and Facet-Specific Stability

Anatase TiO₂ Surface Hydration: Infrared Vibrational Assignment and Facet-Specific Stability

Crystal growth, structural, vibrational assignments, electronic, topological behavior and Hirshfeld surfaces of 1H-imidazole-1-methanol (HIM) single crystal

Crystal growth, structural, vibrational assignments, electronic, topological behavior and Hirshfeld surfaces of 1H-imidazole-1-methanol (HIM) single crystal

Quantum mechanical investigation of the choline chloride/carboxylic acid deep eutectic solvents

Deep eutectic solvents (DES) have received substantial applications and development in the field of green chemistry during the last decade. Using computational density functional theory (DFT), DESs composed of Choline Chloride (ChCl), as the hydrogen bond acceptor (HBA), and six carboxylic acids (CA) including Glycolic acid (Gly), Glutaric acid (Glu), Oxalic acid (Oxa), Lactic acid (La), Itaconic acid (Ita), and Levulinic acid (Lev), as the hydrogen bond donner (HBD), were investigated. Geometry optimization and vibrational frequency assignment were performed by applying three DFT functionals, i.e., B3LYP-D3(BJ), M06-2X, and ωB97XD in combination with Pople’s 6-311+g(d,p) basis set. Then, using of the QTAIM, NBO, and the NCI analyses, different sorts of interactions have been evaluated to indicate the most stable structure between ChCl and various CAs, and the hydrogen bonding in the studied DESs. The results confirm that the Cl ion in choline chloride created a strong hydrogen-bond with HBDs, and the mixed ionic-covalent interaction is the main interaction in construction of the DESs of ChCl with the studied carboxylic acids.

Synthesis, spectroscopic characterization, electronic elucidation, chemical reactivity, topological and molecular docking investigations of cefadroxil sulfoxide

The cefadroxil sulfoxide (CDSO) para-hydroxy derivative, derived from cefadroxil, has enormous significance in pharmaceutical applications. The cefadroxil sulfoxide (CDSO) compound was synthesized and characterized by spectroscopic (FT-IR, FT-Raman, and UV–Visible) assessments. Computational investigations have been carried out concurrently with a B3LYP-6-311++G(d,p) basis set and density functional theory (DFT). The molecular vibrational assignments, chemical reactivity, electronic properties, and optical activities are calculated using gas and different solvent phases. The stable ground state configuration of the given molecular compound is investigated using PES analysis. Furthermore, the chemical behavior of the CDSO was thoroughly investigated for different solvent aspects through HOMO-LUMO, MEP, UV–Visible and electron-hole excitation analyses. The molecular occupancy, virtual occupancy, and overlapping bonding energies are investigated by TDOS, PDOS, and COOP spectrum studies. Fukui function and dual descriptor investigations extend to the chemical reactivity of individual atomic sites. The intra-molecular analysis provided a deeper understanding of the molecular interactions performed by natural bond orbitals (NBO) and non-linear optics (NLO), which provided optical activity for the title compound. Additionally, electron localization function (ELF), localized orbital locator (LOL), and reduced density gradient (RDG) analyses were also accomplished to provide insight into the delocalized orbitals in the header composite. The molecular docking was achieved, and the ligand with 4EVM protein is providing the potential antimicrobial biological activity (binding energy −7.12 kcal/mol) of the CDSO compound.

Impact of physicochemical properties on stabilities of aqueous solutions of potassium 1-fluorobenzoyltrifluoroborate salt

Physicochemical properties of aqueous solutions of potassium 4-fluorobenzoyl-trifluoroborate salt have been studied to know the effect of concentrations and time on its stabilities because these properties are essential to predict and control chemical reactions and, to develop new substances with innovative applications. Here, pH, refractive index, density, conductivity and molar refractivity have been evaluated during 92 days and, the Ka and pKa for all solutions have been calculated. Salt concentrations and time show effects on the densities, pH and conductivities of the solutions while the refractive indexes and molar refractivity remain practically constant during the time studied. The infrared, Raman and UV–vis spectra of acid in gas phase and aqueous solution have been predicted by using hybrid B3LYP/6-311++G** calculations. Intra-molecular halogen OH…F interactions predicted for the acid in both media probably explain the decreasing observed in the conductivity values. Full vibrational assignments of acid and its scaled force constants in both media are reported. The decreasing observed in the f(νBF3) force constants of the three species in both media suggest that the trifluoroborate group plays an important role in the properties of salt. The predicted UV spectrum of acid in aqueous solution compared with the experimental of salt suggest that the anion, acid and salt species are present in aqueous solution, as evidenced by the physicochemical properties. Hence, the presence of three species in solution justify the variations observed in the pH, density, conductivity, force constants and positions of IR and Raman bands related to OH and BF3 groups.

FT-IR, UV–Vis, density functional theory and molecular docking studies on 3,7,11,15-Tetramethyl-2hexadecen-1-ol

The organic molecule of 3,7,11,15-Tetramethyl-2-hexadecen-1-ol is frequently present in plant chlorophyll pigment. The title compound possesses antimicrobial, antibacterial, antioxidant, anti-inflammatory, and anticancer characteristics. The 3TMH molecule are being investigated using Gas Chromatography Mass Spectrometry (GC–MS) analysis, Ultraviolet-Visible (UV–Vis), Fourier Transform Infrared Spectroscopy (FT-IR), and Density Functional Theory (DFT) approach with the Becke,3-parameter, Lee–Yang–Parr (B3LYP) method, 6–311++G (d, p) basis set is used to analyse the geometrical parameters, Highest Occupied Molecular Orbital and the Lowest Unoccupied Molecular Orbital (HOMO-LUMO), and Molecular Electrostatic Potential (MEP) mapping. In the 3TMH molecules, the computed Natural Bond Orbital (NBO) analysis exhibit the high stabilization interaction (intra-inter, hydrogen bonding, and charge delocalization) between the donor and acceptor. The UV–Vis spectra of the maximum absorption correlated with different solvents as determined by Time-Dependent Density Functional Theory (TD-DFT). According to Veda 04, the measured FT-IR spectrum and the theoretical spectra of vibrational assignment with Potential energy distribution (PED%) are in good agreement. The Electron Localization Function (ELF) and Localized Orbital Locator (LOL) mapping has provided an explanation for the chemical bonding within fragments, as well as interactions between the atoms. The strong attraction, strong repulsion, and weak interaction have been estimated Reduced Density Gradient (RDG). Furthermore, the molecular docking examined ligand-protein interaction of least binding energy 6.73 kcal/mol against anti-cancer activity.

Spectroscopic investigation of drug potential towards neuronal firing and analysis of molecular docking on (N-(diaminomethylidene)-2-(2,6-dichlorophenyl) acetamide) using DFT theoretical data evidence

Guanfacine is an alpha-A2 adrenergic receptor agonist used for the treatment of attention deficit hyperactivity disorder. Guanfacine also known as (N-(diaminomethylidene)-2-(2,6-dichlorophenyl) acetamide) and in this work it was investigated by interpreting physico-chemical, structural and biological properties using FT-Raman, FT-IR, NMR and UV–Visible spectral datum along with computational results. The optimized geometry of the molecular structure was sketched and deviation of parametric values has been interpreted. The vibrational analysis along with vibrational assignments was carried out to understand the impact of nitro, methylidine, chloro effects on acetamide base molecule to change in drug mechanism. The molecular charge population delocalization on par with substituent was analyzed and purpose of electron cloud accumulation on different entities was justified. The drug likeness score was calculated and bioavailability was tested. The enzymatic target investigation was made on theoretical results of HyperChem. The vibrational characteristics of the compound were evaluated and the chemical-patrician energy of bonds and their influences on drug property change were tested. Chemical reaction path mechanism was mapped to find the root cause of chemical kinetics to enable antimicrobial activity on the heart of Guanfacine molecule. The doubly degenerate interaction orbitals were viewed and the transitions assigned to facilitate the drug activity were studied. The toxicity profile was evaluated by opting enantiomer and validated by simulating VCD spectrograph. The Guanfacine docked into the active site of 5R7Y and 6MOJ indicates conceal antiviral activity, consistent with results from the PASS database. Using the autodock program, docking molecules (ligand-proteins) were simulated.

Density functional theory and spectroscopic analysis of stigmasterol from Garcinia wightii: Deciphering its inhibitory potential against drug-resistant tuberculosis via insilico molecular docking and molecular dynamics simulations

This study investigates the molecular structure and electronic properties of stigmasterol, isolated from Garcinia wightii, using density functional theory (DFT) alongside experimental techniques including FT-IR, FT-Raman, UV–Vis, 1H and 13C NMR spectroscopy. Theoretical predictions are compared with experimental results, facilitated by vibrational energy distribution analysis for unambiguous vibrational wavenumber assignments. Natural bond orbitalanalyzes reveal donor-acceptor bond energies and electron densities, while Fukui functions identify reactive sites susceptible to electrophilic and nucleophilic attacks. Electronic properties are further explored through various analyzes, unveiling reactive surface sites. Non-covalent interactions are examined using reduced density gradient analysis. Assessment of absorption, distribution, metabolism, and excretion attributes aids in drug discovery efforts. Molecular docking studies against 20 target proteins for antitubercular screening show a stable glide score of -9.52 kcal/mol for the protein 4FDO (Mycobacterium tuberculosis DprE1 in complex with CT319). Molecular dynamics simulations over 100 ns indicate the stability of the ligand-protein complex, suggesting its potential as an antituberculosis agent. Stigmasterol's structural, vibrational, electronic, and topological properties are thoroughly investigated, revealing its ring skeleton with a flexible isooctyl side chain, adhering to C1 point group symmetry. Steric and stereo electronic interactions play crucial roles in conformation and binding to target proteins. Theoretical and experimental analyzes align, confirming the compound's bioactive properties. This comprehensive investigation underscores stigmasterol's potential as a tuberculosis treatment option, providing valuable insights into its structural characteristics and therapeutic possibilities.

Computational aspects of DFT, HOMO-LUMO, PED, molecular docking and basic characterisations of Octadec-9-Enoic Acid (C18H34O2)

Finding a few potential ‘green’ inhibitors has been a long-term goal because these products that are derived from plants enable prescription drug costs reduced, side effects minimised and biodegradable. Known by its common name, Hybanthusenneaspermus (L.) F. Muell, which is a member of the Violaceae family, is a herb or shrub found worldwide in tropical and subtropical climates. Knowing the applicability of H. enneaspermus for the treatment of a variety of acute or chronic diseases with a diverse nature of phytoconstituents will be made easier with the information provided in this comprehensive article. The majority of the information in this research article was gathered from different scientific sources that focused on H. enneaspermus research. Plant extraction, optimised geometry, thorough vibrational assignment, and characterisation of the fundamental vibrational modes of Octadec-9-Enoic Acid were conducted using experimental FT-IR and UV-Vis data in addition to quantum chemistry research. The actual vibrational data were compared to the wavenumbers computed theoretically for the chemical's optimal shape using DFT/B3LYP gradient calculations with the 6-311G ++ (d,p) basis set. A computation has been performed utilising the energy gap between HOMO and LUMO. Intramolecular interactions (NBO), molecular electrostatic potential (MEP) at a specific point p (x,y,z), atomic charge values, NMR & UV-vis computation, and molecular docking studies with protein-ligand interactions were all interpreted using natural bond orbital analysis.

Nucleation, crystal growth, XRD, optical, electrical, PC, SEM, SHG and Z-scan analysis of LHPP for NLO and optical limiting application

High-quality organic L-histidinium 4-nitrophenolate 4-nitrophenol (LHPP) single crystals were grown using an aqueous solution. The crystals were grown using slow evaporation solution technique (SEST) at a temperature of 40°C using a constant temperature bath (CTB). Nucleation growth rates were monitored for various durations using an optical microscope. The crystalline perfection was confirmed through sharp, high-intensity diffraction peaks observed in the theoretical and experimental powder X-ray diffraction (PXRD) analysis, which also confirmed the monoclinic crystal structure with the noncentrosymmetric P21 space group. The crystallite size and strain were calculated using Williamson–Hall coefficient. Vibrational frequency assignments of LHPP were determined using FTIR spectroscopic analysis. Optical properties were studied using UV–Vis NIR spectroscopic studies, which showed that the crystals have very low absorption and high transmittance in the entire visible region. Additionally, the optical energy bandgap (Eg) was calculated and found to be 6.15[Formula: see text]eV. Luminescence properties were studied using fluorescence (FL) analysis. Dielectric investigations were subjected to varying frequencies to study the suitability of the crystal for transistor application. The positive photoconductive (PC) nature of the crystal was confirmed using photoconductivity studies to confirm suitability for photodetector devices that measure the intensity of light rays. Etching studies revealed the growth pattern and the formation of different kinds of etch pits. The surface morphology was studied using scanning electron microscopy (SEM) and electrochemical studies were also carried out. The relative second harmonic generation (SHG) efficiency of the material was also examined and found to be 1.34 times that of standard KDP. The optical limiting and higher-order nonlinear optical (NLO) properties of the grown crystals were studied by the [Formula: see text]-scan method using a Nd: YAG laser functioning at 532[Formula: see text]nm.

Structural reactions, green chemistry solvents, topology surface, electronic and biological studies of 4-(dihydroxymethyl) pyridine-2-carbonitrile – Anti-tuberculosis activity

Spectroscopic properties of 4-(dihydroxymethyl) pyridine-2-carbonitrile have been theoretically scrutinized using DFT technique utilizing B3LYP approach along with 6–311G++(d,p) basis set. Electronic-stability, electronic transitions, and distribution of charge within the molecule were analyzed using FMO and NBO analyses, which involve π*(C13–C14) to π*(C10–C15) transition, with a maximum stabilization energy of 212.33 kcal/mol, which ascertain the molecule's stability. Vibrational assignments for FT-IR and FT-Raman spectrum have been conducted using PED for identifying functional groups. Topological analyses such as ELF, LOL, and RDG provided a comprehensive understanding of the distribution of charged particles across each element within molecule, enabling the identification of electrophilic and nucleophilic sites. DMPC adheres to Lipinski's rule of five, indicating suitability for oral administration similar to other drugs. Investigations using molecular docking were performed to analyze the biological asset of the compound. Protein 6UCR demonstrated superior binding potency with a minimum binding-energy reaching −8.5 kcal/mol, revealing its potential treatment for tuberculosis.

Vibrational assignments of monohydrate dimer of violuric acid by using FT-IR, FT-Raman and UV spectra and DFT calculations in different media

Experimental FT-IR, FT-Raman and UV spectra have been combined with hybrid B3LYP/6–311++G** calculations and the scaled quantum mechanical force field (SQMFF) methodology to study structural and vibrational properties of monohydrated dimer (MD) of violuric acid in gas and aqueous media. Complete vibrational assignments and its scaled force constants are reported together with the corresponding to anhydrous and monohydrate monomer. From four anhydrous C1, C2, C3, C4 monomers, C4 is the most stable in both media. In solution, the initial structure of C2 change to the tautomeric species most stable C4. The MD reveals a higher solvation energy while natural bond orbital (NBO) and atoms in molecules (AIM) calculations support the higher stability of this species due to the six H bonds interactions and to its higher expansion of volume in solution. The MD is the most reactive species, as revealed by the lowest gap value and by high global electrophilicity and most negative global nucleophilicity indexes. Very good concordances are observed among the predicted IR, Raman, 13C NMR and UV spectra and the corresponding experimental ones. Comparisons of predicted 13C NMR and electronic spectra with the experimental one show that those three species of violuric acid could be present in aqueous solution. Similar f(νC=O) and f(νC-O) force constants for the three species are justified by the important delocalization of electrons evidenced in anhydrous and monohydrate species by NBO calculations.

Unveiling the molecular insights of 2-(carboxymethyl) benzoic acid: A density functional theory approach towards structural and biological attributes

Nowadays density functional theory (DFT) is one of the best methods to explore the vibrational modes and structure of the biological system. Quantum mechanical calculations are performed using gas phase and different solvents (DMSO, methanol and water). The derived global reactive parameters, structural and topological study provides the clear insight of the 2-(Carboxymethyl) benzoic acid. Depth studies of DFT proves the existence of hydrogen bonds between donor and acceptor in the compound, which is supportive for the biological applications. In this paper, different experimental and computational simulated FT-IR, FT-Raman, UV–Vis spectral studies are used to explicate vibration assignments of the 2-(Carboxymethyl) benzoic acid. Experimentally observed vibrational frequency is compared with theoretically simulated spectrum. B3LYP method with 6–311++G (d, p) basis set is used in DFT to optimize the 2-(Carboxymethyl)benzoic acid structure. The most stable lower energy conformer is identified using potential energy surface (PES) analysis using Gaussian 16 W software. ESP, HOMO-LUMO, NBO, and QTAIM calculations have evinced an adequate electronic characterization of 2-(Carboxymethyl) benzoic acid. Further, van der Waals and steric interactions among 2-(Carboxymethyl) benzoic acid have been discussed with the help of RDG study. Hirshfeld surface studies establish the existing various interaction among molecules and total packing arrangement of the crystal structure. Due to the high biological activity score, 2-(Carboxymethyl) benzoic acid is a good therapeutic candidate. Lipophilicity analysis of 2-(Carboxymethyl)benzoic acid clearly explicates the bioactivity properties and its effective drug applications. Further, molecular docking investigates that the compound can be used as anticancer medication. The detailed DFT study of the 2-(Carboxymethyl) benzoic acid justified its biological applications of the present communication. The calculated NLO parameters of 2-(Carboxymethyl)benzoic acid evidenced for good efficacy in diverse filed application has been discussed.

Vibrational analysis, DFT computations of spectroscopic, non-covalent analysis with molecular docking and dynamic simulation of 2-amino-4, 6-dimethyl pyrimidine benzoic acid

Vibration assignments were refined through the use of normal coordinate analysis (NCA), one of several spectroscopic computations employed in extensive investigations into the composition of 2-amino-4,6-dimethylpyrimidine benzoic acid (2ADPB). Red-shifting bands revealed N-H-O hydrogen bonding, which is corroborated by optimised geometry results and vibrational analysis. The bond length and angle have been studied through an optimized geometry at B3PW91/6–31 G (d, p) theory. FMO and NBO methods investigate chemical reactions and strength of 2ADPB. Strong intermolecular hydrogen bond interactions O13‧‧‧H27-N25 and O14-H15‧‧‧N16 have been confirmed by structural studies and remains confirmed through BCP on H15-N16, H27-O13 for 2ADPB have sturdy intermolecular hydrogen bonds interactions. MEP categorizes negative and positive sites, visualizing charge accumulation on individual atoms in the molecule. The molecule showed charge transfer, analyzed with descriptors like LOL and ELF. Kirby-Bauer method confirmed findings across bacterial strains. Molecular Docking explored ligand-protein interactions, while pharmacokinetics was studied using drug features.

Structural characterization and biological activity evaluation of Magnoflorine alkaloid, a potential anticonvulsant agent

Magnoflorine (MGF), an isoquinoline alkaloid, emerges as a quaternary aporphine alkaloid derived from L-tyrosine amino acid, found in families Magnoliaceae plants and it presents important biological activity being noted for its effect on the nervous system. In this work, a deep study of structural, vibrational and electronic properties has been carried out for the MGF. From Potential Energy Surface (PES) scan the most stable conformer of alkaloid was identified and geometrical parameters were determined by Density Functional Theory (DFT) using B3LYP/6–311++G** method. A complete vibrational assignment of the normal modes was theoretical and experimentally achieved from FT-IR and Raman spectroscopies and scaled SQM methodology. Electronic transitions observed in UV–visible spectrum in aqueous medium were identified using TD-DFT methodology, with the π→π* transition being the most probable UV signal. The MEPs, the electric charge distribution along with the HOMO and LUMO frontier orbitals were analyzed and the GAP energy values justified the stability of the molecule in aqueous medium. The molecular electrostatic potential map reveals the most favourable region for electrophilic attack on MGF. Molecular docking was used to analyze the anxiolytic biological activity of the title molecule on the GABAA receptor. The results suggest an intermolecular binding capability of MFG toward both intracellular and extracellular domains of GABAA receptor, and the extracellular domain presents a higher affinity by alkaloid. Finally, the biological study infers that MGF could be used as a potential anxiolytic compound.

Theoretical study on the structure, spectroscopic, and current–voltage behavior of 11-Cis and Trans retinal isomers in rhodopsin

In this study, the electronic transport properties of 11-Cis and Trans retinal, components of rhodopsin, were investigated as optical molecular switches using the nonequilibrium Green’s function (NEGF) formalism combined with first-principles density functional theory (DFT). These isomers, which can be reversibly converted into each other, were examined in detail. The structural and spectroscopic properties, including infrared (IR), Raman, nuclear magnetic resonance (NMR), and ultraviolet (UV) spectra, were analyzed using the hybrid B3LYP/6–311 + + G** level of theory. Complete vibrational assignments were performed for both forms utilizing the scaled quantum mechanical force field (SQMFF) methodology. To evaluate the conductivity of these molecules, we utilized current–voltage (I-V) characteristics, transmission spectra, molecular projected self-consistent Hamiltonian (MPSH), HOMO–LUMO gap, and second-order interaction energies (E2). The trendline extrapolation of the current–voltage plots confirmed our findings. We investigated the effect of different electrodes (Ag, Au, Pt) and various connection sites (hollow, top, bridge) on conductivity. The Ag electrode with the hollow site exhibited the highest efficiency. Our results indicate that the Cis form has higher conductivity than the Trans form.

Terahertz spectroscopic study of the dehydration process and hydrogen bonding network of DL-glutamic acid and its monohydrate

The dehydration process involves the dissociation and reorganization of hydrogen bonds, and for the characterization of the dehydration process of amino acid-based hydrates, the analysis of their molecular vibrational modes and hydrogen bonds is still challenging nowadays. In this paper, the dynamic process of the dehydration of DL-glutamic acid monohydrate was monitored using terahertz spectroscopy. Quantitative simulations were performed on DL-glutamic acid and its monohydrate, with vibrational mode assignments and hydrogen bonding network analysis based on Density Functional Theory (DFT) for terahertz absorption peaks. The results show that the hydrogen bond stretching vibration is intermixed with atomic vibration. Specifically, the intermolecular hydrogen bond O4-H9···O2 of DL-glutamic acid exhibits a stronger vibration at 2.43 THz. Furthermore, the intramolecular hydrogen bond O5-H11···O4 in DL-glutamic acid monohydrate shows significant changes in bond length and bond angle at 1.85 THz. These findings validate the effectiveness of terahertz spectroscopy in monitoring the transformation process of the hydrate and the analysis of the hydrogen bond.

Multifaceted investigation of Sulfamerazine: Insights from computational methods, experimental techniques, and molecular simulations

The powerful sulfonamide antibiotic Sulfamerazine has been the subject of in-depth study to clarify its complex molecular interactions. In order to understand Sulfamerazine's pharmacological behaviour and interactions with biological components, this comprehensive study uses computational tools such as Density Functional Theory (DFT) calculations, spectroscopic analyses, and molecular docking simulations. Exploitation B3LYP/6-311++G(d,p) basis set, DFT simulations have provided important new understandings of the structure, vibrational properties, and binding mechanisms of this system. Vibrational assignments have been conducted by analyzing individual vibrational modes and comparing them to experimental data. The molecule's weak interactions have been identified grounded on electron density using Reduced Density Gradient Analysis. Fukui and MEP plot analyses have been employed to pinpoint the molecule's electrophilic and nucleophilic sites. Frontier molecular orbital analysis supported the observation of charge transfer within the molecule. Sulfamerazine is a viable option for further pharmaceutical development, as shown by drug-likeness and ADME (absorption, distribution, metabolism, and excretion) studies. In docking analysis, the inhibitor 6qzh stood out as particularly potent, capable of forming up to three hydrogen bonds, resulting in a binding energy of -8.2 kcal/mol. Molecular dynamics simulations have also shed light on the stability, solubility, and possible interactions of Sulfamerazine in diverse settings. This all-encompassing strategy promises to increase our understanding of the mechanism of action of Sulfamerazine, creating new opportunities for the logical development of more potent pharmaceuticals.