Experimental Wavenumbers Research Articles

Synthesis, Spectroscopic Characterization, Molecular Docking and in Vitro Cytotoxicity Evaluation Studies on 6-Methoxy-8-Nitroquinoline Hydrogen Sulphate: A Novel Cervical Cancer Drug

The 6-Methoxy-8-nitroquinoline hydrogen sulfate (6M8NQHS) molecule has been studied using density functional theory (DFT) with thorough and accurate vibrational and spectroscopic investigations, as well as experimental validation. FT-IR, FT-Raman, and UV-Vis spectroscopy techniques were used to characterize the synthesized 6M8NQHS sample. The optimized molecular structure and harmonic vibrational frequencies of the molecule were calculated using DFT/B3LYP method with a LANL2DZ basis set using the Gaussian 09 program. The computed and experimental vibrational wavenumbers were assigned. The UV-Vis spectrum absorption spectrum of the molecule was observed in the liquid phase (acetone) and also simulated, which shows the π to π* and n to π* electronic transitions of the molecule. Frontier molecular orbital research reveals the molecule’s molecular reactivity and kinetic stability. The molecule’s reactive site is confirmed by the Mulliken atomic charge distribution and molecular electrostatic potential surface analysis. The bioactivity of the molecule was demonstrated by the natural bond orbital analysis. Molecular docking analysis confirms that the 6M8NQHS molecule inhibits the action of human p38a Mitogen-activated protein kinase 14, which is linked to cervical cancer. In addition, the MTT assay was used to determine the in vitro cytotoxicity of the 6M8NQHS molecule against human cervical cancer cell lines (ME180) and human breast cancer cell lines (MDA MB 231), demonstrating that the title molecule inhibits the cervical cancer cell lines more than breast cancer cell lines. As a result, the current research paves the way for the creation of new drugs to treat cervical cancer.

Synthesis, Spectroscopic, Molecular Docking and inhibitory activity of 6-Bromo-2-(4-chlorophenyl)-1H-benzimidazole- a DFT approach

6-Bromo-2-(4-chlorophenyl)-1H-benzimidazole a novel compound was synthesized to treat antimicrobial infections and characterized by FT-IR, FT-Raman, 1H-NMR, UV-Vis. The stable conformer and structural optimization were carried out using the DFT-B3LYP (6-311 ++ G (d, p)) method in Gaussian 16 W. FT-IR and FT-Raman experimental and theoretical wavenumbers with the complete vibrational assignment were reported. NMR of 1H -13C and UV-Vis is calculated at different solvents using the IEF-PCM method. The conductivity, reactivity and stability of the title compound are determined by HOMO-LUMO values. The antibacterial activity was tested against S. aureus and A. niger indicates a significant zone of inhibition than the reference drug ciprofloxacin at the concentration of 25 µg/ml, protein and ligand interaction site in docking was determined by MEP. Finally, the molecular docking between the title and the reference compound ligand with the A. niger / 3EQA were studied and compared the binding energy of the compound at the active sites.

Reactive azo compounds as a potential chemotherapy drugs in the treatment of malignant glioblastoma (GBM): Experimental and theoretical studies

This research work focuses on the synthesis, spectroscopic characterization, DFT studies, and in silico molecular docking of two azo compounds; (E)-6-((4,6-dichloro-1,3,5-triazin-2-yl)amino)-4-hydroxy-3-(phenyldiazenyl)naphthalen-2-yl hydrogen sulfite (compound A) and (E)-6-((4,6-dichloro-1,3,5-triazin-2-yl)amino)-3-((4-formylphenyl)diazenyl)-4-hydroxynaphthalen-2-yl hydrogen sulfite (compound D) to determine their application as chemotherapeutic drug for the treatment of the malignant glioblastoma multiforme (GBM). The experimental and theoretical vibrational wavenumbers of the synthesized compounds were compared and observed to be in good agreement. Density functional theory (DFT) at the B3LYP/6-311++G(d,p) level of theory was further utilized to investigate the frontier molecular orbitals, Fukui reactivity functions, excitation energies, and the natural bond orbital (NBO) analysis for the investigation of the bonding interactions of the studied compounds. The binding affinities of the studied compounds and the standard drug (temozolomide) against four different GBM proteins: 6bft, 6s79, 1Is5, and 1z2b was investigated using in silico molecular docking approach. Compound A displayed the highest relative binding affinities of -8.7 and -8.6 with 6s79 and 1Is5 proteins respectively compared to compound D with the binding affinity of -7.6. Both compounds A and D showed little to no interaction with 1z2b protein but their binding affinities with 6bft, 6s76 and 1Is5 proteins are relatively higher than those of the standard drug. Pharmacological studies also showed that both compounds exhibit good solubility in water resulting in good lipophilicity. With the obtained results, it is safe to say that the compounds and their derivatives could be considered as a potential chemotherapeutic drug for the treatment of glioblastoma or as a precursor for the synthesis of other pharmaceutical products.

The effect of intrinsic instability on the surface topography of spherical 2-acetylfuran flame

The intrinsic instability of 2-acetylfuran (2-AF) expanding flame has been investigated at initial temperatures of 453–493 K, pressures of 1–3 bar, and equivalence ratios of 0.8–1.4. The linear stability theory was used to analyze the influence of the initial temperatures, initial pressures, and equivalence ratios on the 2-AF flame intrinsic instability. Moreover, an image processing technique was applied to obtain the experimental cell-wavenumber from the topography of 2-AF cellular flame to quantitatively analyze the local cell proliferation. The topography of the 2-AF expanding flame shows that the initial pressures and equivalence ratios are the two influential factors to its intrinsic instability. More specifically, the higher the initial pressures, as well as the equivalence ratios, the earlier the time of the flame becomes unstable. Furthermore, according to the comparison between the local experimental and theoretical wavenumbers, it is found that the average local experimental wavenumber falls within the unstable zone predicted by the linear stability theory. Last but not least, the cell-wavenumber distribution in the different regions on the 2-AF expanding flame surface indicates that the initial crack has a weaker shaping effect on the flame surface than the formation of small spontaneous cells.

Revised Energy Levels of Atomic Lanthanum Considering Hyperfine Structure

Abstract The experimental wavenumbers of 2118 spectral lines from calibrated Fourier transform (FT) spectra have been used to determine revised energy values of 405 fine structure levels of atomic lanthanum, 264 levels of even and 141 levels of odd parity, respectively. For the determination of the level energies a weighted global fit of the center-of-gravity (cg) wavenumbers of all 2118 spectral lines has been done. All lines have been classified previously by different spectroscopic methods and by different authors. In order to achieve high accuracy, the hyperfine (hf) structure was taken into account when determining the cg wavenumbers from the FT spectra. The total uncertainty for all revised energy levels lies below 0.007 cm−1. A compilation of all revised energy levels along with their hf structure data is given, as well as a list of the spectral lines used in this investigation.

Synthesis, spectral, structural and antimicrobial activities of Ethyl-4-｛[-(1-(2-(4-nitrobenzoyl)hydrazono)ethyl]｝-3,5-dimethyl-1H-pyrrole-2-carboxylate

A new ethyl-4-{[-(1-(2-(4-nitrobenzoyl)hydrazono)ethyl]}-3,5-dimethyl-1H-pyrrole-2-carboxylate (ENBHEDPC) has been synthesized, characterized (FT-IR, 1H and 13C NMR, UV-Visible, DART-Mass spectroscopy, elemental analysis) and evaluated for antituberculosis and antibacterial activity. Quantum chemical calculations have been performed by DFT level of theory using the B3LYP functional and 6–311++G(d,p) as basis set. The 1H and 13C NMR chemical shifts and electronic transitions are calculated using gage including atomic orbitals (GIAO) and time dependent density functional theory (TD-DFT) approach in DMSO as solvent. Combined theoretical and experimental wavenumber analyses confirm the existence of dimer. Hydrogen bonding and other multiple interactions have been analyzed by Bader's ‘Atoms in molecules’ AIM theory in detail. The intermolecular hydrogen bond energy of dimer is calculated as -12.28 kcal/mol. The calculated thermodynamic parameters show that reaction is exothermic and non-spontaneous at room temperature. The local reactivity descriptors analyses determine the reactive sites within molecule by nucleophilic attack. Nonlinear optical (NLO) behavior of title compound is investigated by the computed value of the first hyperpolarizability (β0). The synthesized compound show good antimicrobial and antituberculosis activity.

Voltage selection of physisorbed or chemisorbed 4-cyanobenzoate on a nanostructured silver electrode and the dual electronic structure of charged metal–molecule hybrids

Applied electric potentials tune SERS wavenumbers due to vibrational Stark effect, but some modes of 4CNB− show two differentiated regions, being redshifted at more negative potentials than the potential of zero charge of the electrode but remain unshifted at positive potentials. DFT calculations have been carried out for a model where 4CNB− is linked through the carboxylate [Agnq-OOC(4CNB-)]q-1 or the nitrile [Agnq-NC(4CNB-)]q-1 to stick-like silver clusters [Agn]q with different densities of charge (qeff = q/n). The comparison between calculated and experimental wavenumber shifts points out that 4CNB− is always adsorbed through the carboxylate. The dual behaviour of the wavenumbers is due to the existence of two types of electronic structure of the metal–molecule hybrid. Physisorbed (P-hybrid, repulsive) or chemisorbed (C-hybrid, attractive) surface complexes are selected by the sign of the surface excess of charge of the electrode. The electronic structure of weakly bonded P-hybrid is very sensitive to the voltage and their wavenumbers are continuously shifted, while the wavenumbers of the strong C-hybrid remain almost unshifted. This result proves the dual nature of the electronic structure of molecules bonded to charged metal electrodes or nanoparticles which can be responsible of the qualitative changes observed in electrochemical or molecular electronics experiments.

Investigating acoustics and wave behaviour in cross-laminated timber panels

Cross-laminated timber (CLT) is a timber product that is becoming increasingly popular in construction in NZ because of the ability to prefabricate panels off-site, as well as being lightweight and sustainable compared to other building materials. There is currently a lack of information on its acoustical properties, as the complex geometry through the thickness means it is difficult to model and predict sound transmission. The WFE (wave and finite element) method has been employed as it allows for a small segment of a material to be modelled using standard FE methods and can incorporate several material layers. It then requires finding the mass and stiffness matrices of the segment and post-processing them to determine the wave behaviour of the structure as a whole. The WFE method was used to model the sound transmission of several different CLT panels and these results were compared against measurements taken by the National Research Council Canada. In-house testing was also performed to obtain experimental wavenumbers, and these were also compared to wavenumbers produced by the WFE method.

Quantum chemical, spectroscopic investigations, molecular docking and cytotoxic evaluation of 1-Methyl-indole-3-carboxaldehyde

Abstract 1-Methyl-indole-3-carboxaldehyde (MEICA) molecule was characterized experimentally using spectroscopic techniques like FT-IR, FT-Raman and UV-Vis. The optimized molecular structure, vibrational and electronic properties of the title compound were calculated by using density functional theory (DFT) method and compared with the experimental results. The color map and contour map obtained from electron Localization Function (ELF) and Local Orbital Localizer (LOL) helps to investigate the electron delocalization in the molecule. The experimental and theoretical wavenumbers of the title molecule were assigned on the basis of potential energy distribution (PED) using VEDA 4.0 program. The charge delocalization and hyper conjugative interactions of the MEICA molecule were investigated using natural bond orbital (NBO) analysis. The HOMO-LUMO energy gap and related molecular properties were calculated. The electronic transitions were performed by TD-DFT calculations and validated experimentally. The Molecular electrostatic potential (MEP) contour maps and Fukui function analysis were performed to visualize the charge distribution in the molecule. The molecular docking analysis reveals that the MEICA ligand shows better inhibitory activity against CK2 which causes lung cancer. The cytotoxic study was performed against human lung cancer cell lines (A549) with IC50 value of 168 μg mL−1. Hence, the MEICA molecule can be used as a drug for the treatment of lung cancer.

Cellularization characteristics of ethyl acetate spherical expanding flame

The cellular instability of ethyl acetate (EA) premixed flame has been studied theoretically and experimentally under different initial temperature, pressure and equivalence ratio. The constant pressure method (CPM) was used to determine the laminar burning velocity of EA spherical expanding flame in this research. In addition, the cellular evolution image of EA spherical expansion flame surface was obtained using high-speed schlieren technology. The image processing technology combined with three-dimensional reconstruction algorithm was used to extract and reconstruct the flame surface crack length, the number of cells on the flame surface, cellular area and cellular length scale. From the quantitative analysis of surface crack and cellular structure of EA flame, it can be seen that the evolution of flame surface crack and surface cellular structure is largely affected by equivalence ratio and initial pressure. With the increase of initial pressure or equivalence ratio, the earlier the flame surface cracks and cell formation. Furthermore, according to the cellular length scale in different radius, the wavenumber was deduced, and compared with the theoretical curve, it is found that the experimental wave numbers have the same evolution trend. Although, when the equivalence ratio is 1.4 with high Peclet number, the experimental wave numbers are somewhat beyond the boundary of the peninsula curve due to the influence of the nonlinear effects, the trend is consistent with the theoretical results.

Laser‐induced phonon and magnon properties of NiO nanoparticles: A Raman study

AbstractIn the present study, the influence of laser intensity on phonon and magnon properties of nickel oxide (NiO) nanoparticles were extensively studied using room temperature Raman spectroscopy. The required NiO nanoparticles were synthesized using a simple sol–gel method. The structural and morphological properties were characterized using powder X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), and transmission electron microscopy (TEM) techniques. The rarely reported surface optical (SO) phonon modes of NiO nanoparticles were observed and well‐studied using the dielectric continuum (DC) model. A mismatch between the experimental and DC model SO phonon wavenumbers were observed and is attributed to one magnon‐induced first order phonon shift. The difference between the experimental and DC model SO phonon wavenumbers were reduced with increase in laser power, which indicates the diminishing behavior of magnon excitations. The laser power dependency of highly distinguishable two magnon (2 M) excitation of NiO nanoparticles were well studied. The 2 M modes were experienced a red shift and decrease in intensity with increase in laser power.

Noncontact Damage Topography Reconstruction by Wavenumber Domain Analysis Based on Air-Coupled Ultrasound and Full-Field Laser Vibrometer.

Noncontact ultrasonic detection technology is an effective method to detect damage in time. This paper proposes a noncontact damage detection system based on air-coupled ultrasound and full-field laser vibrometer, which realizes the excitation of relatively single-mode guided waves and the wavefield automatic detection. The system performance is verified through experiments, and the experimental wavenumber is consistent with the theoretical dispersion characteristics of the Lamb wave in the A0 mode. Based on this system, the topography reconstruction algorithms, including the Wavenumber Filtering Algorithm and Spatial Wavenumber Algorithm, were tested and compared with the aluminum alloy plate and the carbon fiber reinforced polymer plate. The results show that, based on the air-coupled ultrasound and full-field laser vibrometer detection system, the Spatial Wavenumber Algorithm has better imaging error and contrast, and the damage edge detection is smoother.

Isomerism, conformation, and structure of Bis(4,4-dimethyl-1-phenylpentane-1,3-dionato)copper(II); A theoretical and spectroscopy approach

Cis and trans isomerism, conformers, molecular structure, relative energies, spectroscopic analysis, metal-ligand strength, and complete vibrational assignment of bis(4,4-dimethyl-1-phenylpentane-1,3-dionato) copper (II), Cu(dmpd)2, were investigated by applying calculated parameters such as density functional theory (DFT), Atoms in Molecules (AIM) study at the B3LYP/6-311G(d) level of theory and experimental techniques contains of vibrational spectra and UV spectroscopy. A comprehensive assignment of the experimental bands of Cu(dmpd)2 has been done. The DFT and spectroscopy techniques applied to consider the assessment of methyl and phenyl and t-But substituents in the β-position on the geometrical and vibrational analysis of complexes. So, the structure, Cu-O strength of the complex, UV spectrum, and vibrational bands of Cu(dmpd)2 compared to bis(benzoylacetonato) copper (II), Cu(bzac)2 and bis(2,2,6,6-tetramethylheptane-3,5-dionato)copper(II), Cu(tmhd)2, by the mentioned theoretical and experimental techniques. All of the simulated and spectroscopic methods supported that the Cu-O bond strength of Cu(dmpd)2is closeto Cu(bzac)2 and more than that Cu(tmhd)2 complex. Comparing the experimental and theoretical vibrational wavenumbers indicates that the transform is the major configuration in the specimen, which agrees with reported the single crystallography results.

Diethyl (2-Amino-3-Cyano-4H-Chromen-4-yl)Phosphonate and Its Halogenated Derivatives as Effective Drug: A Theoretical and an Experimental Spectroscopic Study

Theoretical calculations of geometrical structure and vibrational wavenumbers, nuclear magnetic behavior and natural bond orbital (NBO) analysis were carried out using density functional (DFT/B3LYP) method with 6-311++G(d, p) as basis set for diethyl (2-amino-3-cyano-4H-chromen-4-yl)phosphonate (DACHP; 1), diethyl (2-amino-6-chloro-3-cyano-4H-chromen-4-yl)phosphonate (CDACHP; 2) and diethyl (2-amino-6-bromo-3-cyano-4H-chromen-4-yl)phosphonate (BDACHP; 3). The global reactivity descriptors are also calculated and compared at same level of theory for all the three molecules. The FT-IR spectra of the compounds under study were measured in their condensed state. The calculated scaled vibrational wavenumbers were found in good agreement with the experimental wavenumbers. Hyper-conjugative interactions and charge delocalization within the molecules were studied using NBO analysis to explore their stability. 1H NMR and 13C NMR chemical shifts of the title molecules were calculated by the GIAO method and compared with experimental results, and good correlations were accomplished. Molecular docking studies were performed for all the three molecules (1–3) to elicit their possible potential as an effective drug.

Density Functional Theory Calculation and Raman Scattering of the Antihistamine Ebastine

The vibrational properties of ebastine have been investigated by density functional theory (DFT) calculations and Raman scattering experiments. The DFT calculation was performed with geometry optimization and harmonic vibration using the B3LYP function with the 6-31G(d) basis set. The DFT calculated spectrum of ebastine is in good agreement with Raman scattering experiments. A good linear correlation between calculated and experimental wavenumbers has been obtained in the spectral range of 500–3250 cm–1. Also, the calculated bond lengths and bond angles of the ebastine molecule are consistent with reported X-ray diffraction results. The deviations of bond lengths and bond angles are smaller than 0.034 A and 3.1°, respectively. In addition, the experimentally observed vibrational modes have been assigned and the characteristic modes of the three parts benzhydryloxy, piperidine-butanone, and tert-butylphenyl of the ebastine molecule have been discussed, which would be helpful for future degradation and activity studies of ebastine.

Spectroscopic characterization, DFT studies, molecular docking and cytotoxic evaluation of 4-nitro-indole-3-carboxaldehyde: A potent lung cancer agent.

The 4-nitro-1H-indole-carboxaldehyde (NICA) molecule was characterized experimentally using FT-IR, FT-Raman and UV-Vis spectra, and it was studied theoretically using DFT calculations. The optimized structure of the NICA molecule was determined by DFT calculations using B3LYP functional with cc-pVTZ basis set. The electron localization function (ELF) and local orbital localizer (LOL) studies were performed to visualize the electron delocalization in the molecule. The experimental and theoretical wavenumbers of the title molecule were assigned using VEDA 4.0 program. The charge delocalization and stability of the title molecule were investigated using natural bond orbital (NBO) analysis. Frontier molecular orbitals (FMOs) and related molecular properties were calculated. UV-Vis spectrum was calculated theoretically and validated experimentally. The reactive sites of the molecule were studied from the MEP surface and Fukui function analysis. The molecular docking analysis reveals that the NICA ligand shows better inhibitory activity against RAS, which causes lung cancer. The in vitro cytotoxic activity of the molecule against human lung cancer cell lines (A549) was determined by MTT assay. Thus, the NICA molecule can be used as a potential candidate for the development of the drug against lung cancer.

Structural and spectroscopic investigation of the chalcones (E)-1-(4-aminophenyl)-3-(4′-ethoxyphenyl)-prop-2-en-1-one and (E)-1-(aminophenyl)-3-(4′-methoxyphenyl)-prop-2-en-1-one

In this study, two 4′-aminochalcones with structural similarity were structurally characterized using the NMR technique of 1H and 13C. Polycrystalline samples of these chalcones were analyzed by FT-Raman and ATR-FTIR spectroscopy at room temperature in the regions 40-4000 cm-1 and 400-4000 cm-1, respectively. The DFT calculations using the B3LYP functional with 6-311 G(d,p) basis set were performed, revealing the optimized molecular geometry and the vibrational wavenumbers for these chalcones. Conformational analysis was done from the optimized structures to obtain different conformers. The calculated harmonic vibrational wavenumbers were scaled to improve the agreement between theoretical and experimental wavenumbers. A complete vibrational assignment using Potential Energy Distributions (PED) was provided for the observed Raman and infrared spectra. The scaled wavenumbers were found to be in good agreement with experimental wavenumbers. Furthermore, a comparative structural and vibrational analysis was performed. The structural analysis allowed us concluding that in addition to differences in the position 4′ – where one chalcone has a methoxy group and the other, an ethoxy group – the molecular conformation of them is significantly different, especially regarding the torsion angles linking the enone chains with the rings of these chalcones. The vibrational analysis allowed us to identify all Raman and infrared bands of the two chalcones, highlighting the main differences and correspondences between them.

Determination of the elastic constants in the classical vibrational model of the CO2 molecule

In this article, we report an experimental method to calculate the values of the elastic constants that correspond to longitudinal and transverse vibrations in the classical model of the CO2 molecule. In classical molecular physics, the CO2 is treated as a linear array of three point-particles that interact by a harmonic coupling. The experimental wavenumbers of the normal modes of vibrations of CO2 were obtained from IR spectroscopy on an atmospheric air sample, and they were applied the calculation of the respective normal mode elastic constants. This article does not provide new research in molecular physics, but it is rather made for teaching purposes.

Monomeric or dimeric? A theoretical and vibrational spectroscopic approach to the structural stability of 5-(4-metoxy benzoyl)-6-(4-metoxyphenyl)-3-methyl-2-thioxo-2,3-dihydropyrimidine-4(1H)-on

The structural and the spectral characteristics of a pyrimidine derivative, 5-(4-metoxybenzoyl)-6-(4-metoxyphenyl)-3-methyl-2-thioxo-2,3-dihydropyrimidine-4(1H)-on (BPOP) was studied using density functional theory methods (DFT/B3LYP) employing 6-31G(d), 6-31G(d,p), 6-311G(d) and 6-311G(d,p) basis sets. Two BPOP molecules form a dimeric structure linked over two mutual N–H⋯SC hydrogen bonds on each of the pyrimidine rings. The quantum chemical calculations of the optimized molecular structures, the energies and IR & Raman spectra of the monomeric and the dimeric forms of BPOP have been performed. The HOMO-LUMO and the molecular electrostatic potential surface (MEP) have also been plotted. The thermodynamic functions including enthalpy, entropy and heat capacity values and Mulliken charges of both structures have been calculated. The detailed assignments of vibrational modes have been made on the basis of potential energy distribution (PED). More accurate new scaling factors were obtained for the four basis sets. It was concluded that the experimental wavenumbers are in better agreement with the results of the dimeric structures calculated by all the methods. B3LYP/6-311G(d) method regenerated the best calculated values among the others.

ON THE ACCURACY OF AVAILABLE WAVENUMBER VALUES FOR ELECTRONIC-VIBRO-ROTATIONAL TRANSITIONS OF THE H2 MOLECULE

All published to date experimental wavenumber values (ν, cm–1) for electronic-vibro-rotational transitions of the H2 molecule are statistically analyzed in the vacuum wavelength range 1/ν = 600—610 nm. It is shown that a direct comparison of all datasets of various authors is blocked by the absence of deconvolving of measured spectra, blending of neighbor lines (an overlap of their profiles), and fragmentary data of most studies. Therefore, it is proposed to compare all available data with the dispersion curve of a high-resolution spectrometer by measuring and deconvolving the H2 spectra. An experimental study of such an opportunity showed that the proposed approach makes it possible not only to analyze the scatter of available data on 1/ν and ν (standard deviations are about 0.003 nm and 0.08 cm–1), but also to obtain more reliable datasets with uncertainties (95% confidence intervals) less than 0.0006 nm and 0.02 cm–1 respectively.