FT-Raman Spectra Research Articles

Supramolecular structure and spectroscopic characterization of new 1,3,5-triaza-2-boracyclohex-3-en derivative formed under mild conditions between 2-imino-4-thiobiuret and boric acid

Reaction of 2-imino-4-thiobiuret with boric acid (in molar ration of 1:1) in aqueous solution at the mild conditions leads to formation of a heterocyclic compound of 2,2-dihdroxy-4-amino-6-thio-1,3,5-trihydrotriaza-2-boracyclohex-3-en (1). This compound crystallizes directly from the reaction solution after a few days, giving light yellowish transparent monoclinic crystals (P21/n). X-ray single crystal analysis shows that the heteroring and the thio- and amine groups are co-planar, whereas the plane of hydroxyl groups linked to boron are almost perpendicular to plane of the ring. The 2,2-dihdroxy-4-amino-6-thio-1,3,5-trihydrotriaza-2-boracyclohex-3-en molecules are arrangement via O–H...S hydrogen bonds in the stacks along b-axis, and the stacks are interacting each other via N–H...O hydrogen bonds forming a three-dimensional supramolecular architecture. The qualitative and quantitative intermolecular interactions in the crystal were analyzed using the Hirshfeld surface and 2D-fingerprint plots. The compound was also characterised by the FT-IR and Raman spectroscopy. The IR and FT-Raman spectra were made for protiated (1) and its deuterated analogue (1d). The IR and FT-Raman spectra for molecule in the gas-phase were calculated using DFT. DFT calculations and the isotropic frequency shift are helpful in assignments of the vibration bands. The calculated HOMO and LUMO energy gap explain the charge transfer interactions taking place within the molecule.

Physicochemical Characterization of the Loganic Acid-IR, Raman, UV-Vis and Luminescence Spectra Analyzed in Terms of Quantum Chemical DFT Approach.

The molecular structure and vibrational spectra of loganic acid (LA) were calculated using B3LYP density functional theory, the 6–311G(2d,2p) basis set, and the GAUSSIAN 03W program. The solid-phase FTIR and FT-Raman spectra of LA were recorded in the 100–4000 cm−1 range. The assignment of the observed bands to the respective normal modes was proposed on the basis of the PED approach. The stability of the LA molecule was considered using NBO analysis. The electron absorption and luminescence spectra were measured and discussed in terms of the calculated singlet, triplet, HOMO, and LUMO electron energies. The Stokes shift derived from the optical spectra was 20,915 cm−1.

Experimental and computational investigation on spectroscopic characterization, molecular modeling and biological evaluation of 3, 3′, 4′7-tetrahydroxyflavone, 3, 3′, 4′7-tetrahydroxyflavone-6-methoxymethane against in A549 cells

The Molecular structural, vibrational, frequencies electronic and potential energy distribution of 3, 3′ , 4′7-tetrahydroxyflavone and 3′, 4′7-tetrahydroxyflavone-6-methoxymethane molecules have been carried out using the techniques of FT-IR and FT-Raman spectra with the aid of computational calculations and compared with experimental calculations. The electronic properties, such as highest occupied molecular orbital and the lowest unoccupied molecular orbital energy levels, molecular electrostatic potential and atomic charges analysis were performed at above levels. The correlation graphs of observed versus calculated vibrational frequencies were plotted and density functional theory gave better wavenumber agreement than others. Molecular docking study show that the intermolecular hydrogen-bonding interactions and binding free energy of -8.4 kcal/mol and -8.1 kcal/mol between 3THDFN and 6THDFN with 1AO6 protein were reported and this study supported the in designing structure-based Human Serum Albumin (HSA) receptors may be of significant biological and pharmaceutical importance. In additional, the in vitro cytotoxicity of compounds confirms the anticancer activity against human lung cancer cell lines was assessed in 24-h tetrazoliumbromide-dye (MTT) cytotoxicity assays. Hence, the present investigations pave the way for the development of lung cancer drugs (A549).

Isomers of Biologically Active 2-Aminopyrimidinium Picrate through Intrinsic Reaction Coordinate Analysis and Spectroscopic Measurements

In the present study, the isomeric forms of a biologically active 2-aminopyrimidinium picrate (2APP) cocrystal were investigated using spectroscopic measurements (FT-IR and FT-Raman) and density functional theory calculations. The vibrational assignments of IR and Raman peaks were predicted and the experimental FT-IR and FT-Raman spectra of the condensed phase of 2APP were compared with the simulated one. The intrinsic reaction coordinate (IRC) analysis was performed on all the possible reaction pathways to identify the isomeric forms of 2APP and transition state geometry. From the IRC analysis, a relatively stable form (named as isomer 2) has been identified in addition to the existing isomeric form (isomer 1) in the crystalline packing of 2APP. The presence of non-covalent interactions within the isomeric forms of 2APP was investigated with the help of quantum topological atoms in molecules analysis. Reactivity descriptors and charge delocalization from lone pair to acceptor entities of both the isomers were predicted to validate the interactions present in the molecule and also to understand the charge distribution within the molecule.

Ex Vivo Vibration Spectroscopic Analysis of Colorectal Polyps for the Early Diagnosis of Colorectal Carcinoma.

Colorectal cancer is one of the most common and often fatal cancers in humans, but it has the highest chance of a cure if detected at an early precancerous stage. Carcinogenesis in the colon begins as an uncontrolled growth forming polyps. Some of these polyps can finally be converted to colon cancer. Early diagnosis of adenomatous polyps is the main approach for screening and preventing colorectal cancer, and vibration spectroscopy can be used for this purpose. This work is focused on evaluating FTIR and Raman spectroscopy as a tool in the ex vivo analysis of colorectal polyps, which could be important for the early diagnosis of colorectal carcinoma. Multivariate analyses (PCA and LDA) were used to assist the spectroscopic discrimination of normal colon tissue, as well as benign and malignant colon polyps. The spectra demonstrated evident differences in the characteristic bands of the main tissue constituents, i.e., proteins, nucleic acids, lipids, polysaccharides, etc. Suitable models for discriminating the three mentioned diagnostic groups were proposed based on multivariate analyses of the spectroscopic data. LDA classification was especially successful in the case of a combined set of 55 variables from the FTIR, FT Raman and dispersion Raman spectra. This model can be proposed for ex vivo colorectal cancer diagnostics in combination with the colonoscopic extraction of colon polyps for further testing. This pilot study is a precursor for the further evaluation of the diagnostic potential for the simultaneous in vivo application of colonoscopic Raman probes.

DFT study of conformation, hydrogen bonds, IR, and Raman spectra of the sodium salt of p-hexasulfonatocalix[6]arene DFT

• The FTIR and FT Raman spectra of p -hexasulfonatocalix[6]arene hexasodium salt were studied. • The structural optimization and normal mode analysis were performed for p -hexasulfonatocalix[6]arene hexasodium salt. • The IR and Raman spectra of p -hexasulfonatocalix[6]arene hexasodium salt were calculated and interpreted. The vibrational spectra of p -hexasulfonatocalix[6]arene hexasodium salt ( SC6 ) and p ‑ tert -butylcalix[6]arene ( TB6 ) were studied. The comparison of the IR spectra SC6 and TB6 allows to distinguish bands of tert ‑butyl and sulfonate groups. The structure and the vibrational spectra of the SC6 molecule were calculated for the conformations of the compressed cone and the double partial cone . For the molecule SC6 , the conformation of a compressed cone is the most stable, and the conformation of a double partial cone is 43.6 Kcal/mol less stable. When replacing tert ‑butyl groups with sulfonatel groups, the cavity size of calixarene molecules increases from 5.22 ( TB6 ) to 7.80 Ǻ ( SC6 ). In the sodium salt of the SC6 molecule, six sodium ions are coordinated with the oxygen atoms of the sulfonate groups. Under the influence of sodium ions, the electron density is redistributed in the SC6 molecule, and its supramolecular properties change. The transition from TB6 to SC6 increases the ionization energy, electronic affinity, chemical potential and dipole moment. In the SC6 molecule, the frontal orbitals are located on aromatic and sulfonate groups. Due to these orbitals, calixarenes interact with biological objects. Optimized geometry and atom numbering for SC6 in the conformation compressed cone .

Synthesis, spectroscopic (FT-IR, FT-Raman, NMR & UV-Vis), reactive (ELF, LOL, Fukui), drug likeness and molecular docking insights on novel 4-[3-(3-methoxy-phenyl)-3-oxo-propenyl]-benzonitrile by experimental and computational methods

The spectroscopic analysis such as FT-IR, FT-Raman, UV-Vis and NMR are conducted for the synthesized molecule by both experimental and theoretical approach. The theoretical computations were achieved by DFT method with B3LYP functional and 6–311 ++ G (d, P) basis set. Firstly the geometrical parameters obtained by DFT are compared with the related experimental parameters. Experimental FT-IR and FT-Raman spectra of the title molecule have been acquired. The vibrational analysis is conducted and the assignments concerned to the observed bands are mentioned through the potential energy distribution (PED). The GIAO method was employed for theoretical NMR analysis and the results are compared with experimental chemical shifts. In accumulation to these analyses NLO, NBO, FMO and MEP analysis have been conducted to understand the nature of the molecule. ELF and LOL were performed. The drug likeness and molecular docking studies also conducted. The potency of inhibition of molecule against MPRO and PLPRO receptors has been performed using molecular docking studies.

Multidisciplinary Studies on Canvas Nature of Paintings at IFIN-HH Romania

Radiocarbon dating of pictorial support is usually less used. It is accepted for paintings with the estimated age older than the Stradivarius limit (ca. 1600 - 1650 CE) as stated by A.J.T. Jull in 1997, and not as an authentication method. Considering this, a seventeenth century oil-based painting (Main Case Study) is reported. Based on the results obtained as terminus post quem , the painting cannot be attributed to the famous painter from the classical period, considered to be the author, according to the signature. Two other recently solved cases (Sample 1 and Sample 2) are briefly recorded and the information obtained was used for a more accurate interpretation of the Main Case Study. The multidisciplinary research aimed to put together, for the first time in the RoAMS Laboratory Romania, the information obtained through elemental analysis, ATR-FTIR, FT-Raman and XRF spectrometry. Radiocarbon dating process includes a comparative description of pictorial fragment pretreatments, of the textile fiber graphitization stage, and of AMS measurements used for determinations of isotopic ratio of carbon species, and general process parameter δ 13 C, of percent of Modern Carbon, and Conventional Radiocarbon Age, and of the Standard Deviations. The fragment of (Main Case Study) was first investigated using both FT-Raman and ATR-FTIR spectrometry. The spectra obtained reveal that the painting surface was covered with a thick layer of linseed oil, which hinders a complete analysis of the pigments through FT-Raman and ATR-FTIR spectrometry. However, the white pigment (lead white) and primer (calcium carbonate) were successfully identified. The findings from ATR-FTIR and FT-Raman spectra provide reliable information about the contaminants, information that is further used to select the most appropriate dating strategy. Before the AMS measurements, the cleaned textile fibers were investigated by elemental analysis, ATR-FTIR and micro-DRIFT spectrometry. The data obtained were compared with known natural and artificial textile fibers. The results reveal an almost complete decontamination, which additionally underlines the assumption that the textile support used exhibits a synthetic nature. Most likely, the canvas was made of synthetic nylon 6.6 fibers on a texture close to sailboat, used for sailing in the mid-twentieth century. The findings were finally confirmed by radiocarbon dating. 14 C/ 12 C isotopic ratios were close to RoAMS Laboratory background level, certifying a raw material from fossil deposits. The other fragments of canvas, those from recently solved cases (Sample 1 and Sample 2) are supposed to belong to the first part of the seventeenth, or to nineteenth / twentieth centuries (where the presumptions were made, and where the final results are placed, for Main Case Study). The comparative data reveal different particularities observed for each situation, offering pro and con arguments in determining the fibers age(s). The information provided by radiocarbon dating, elemental analysis and XRF spectrometry is in good agreement and demonstrates that it is unlikely that the authors designated for each case were those who created the paintings. The XRF spectrometry investigation highlighted the use of primers or pigments that generally appeared in the painting technique after the date when the painting creation was estimated.

Sulfation of arabinogalactan with sulfamic acid under homogeneous conditions in dimethylsulfoxide medium.

Sulfation of larch wood arabinogalactan (AG) with sulfamic acid in dimethylsulfoxide (DMSO) medium in the presence of urea was studied for the first time. The use of DMSO as a solvent instead of more toxic 1,4-dioxane allows to sulfate AG under homogeneous conditions. The sulfated AG with a high sulfur content (12.0–12.5 wt %) was produced by sulfation at a temperature of 85–90 °C, the molar ratio of AG / sulfating agent equal to 1:0.85 during 2–3 h. The introduction of sulfate groups into the structure of arabinogalactan was confirmed by the appearance of new absorption bands in FTIR and FT Raman spectra, characteristic for the vibrations of the sulfate groups. It was proved by 13C NMR spectroscopy that the predominant substitution of the primary hydroxyl groups at C6 carbon atoms of the terminal galactose units of main and side chains of arabinogalactan takes place. Simultaneously, the hydroxyl groups associated with C2 and C4 carbon atoms of galactose unit of the main chain are only partially sulfated. According to results of GPC study, the sulfated AG is characterized by a narrow molecular weight distribution with an average molecular weight of 18.8 kDa and a polydispersity of 1.3.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00226-021-01341-2.

Experimental and theoretical approach on third-order optical nonlinearity of a highly efficient anthracene-based chalcone derivative for optical power limiting

Herein the study reports a dual approach on theoretical and experimental studies of nonlinear optical properties of a novel chalcone derivative, (2E)-1-(Anthracen-9-yl)-3-(biphenyl-4-yl)prop-2-en-1-one [biphenyl-ANC]. The obtained experimental results have been supported by the theoretical calculations performed by density functional theory. The FT-IR, FT-Raman, and UV-visible absorption spectra were recorded and analyzed. The structural, electronic and charge transfer analyses were computed by B3LYP level of theory with 6–311++G(d,p) basis set. The second-order hyperpolarizability has been theoretically predicted using B3LYP and CAM-B3LYP hybrid functional. The third-order nonlinear optical properties, along with the optical limiting studies of biphenyl-ANC in polar and nonpolar solvents, were carried out by z-scan technique using Q-switched Nd:YAG laser with 5 ns pulses at 532 nm. The z-scan results reveal that the compound can act as a promising candidate for photonic and optoelectronic applications.

Comparative study of molecular docking, structural, electronic, vibrational and hydrogen bonding interactions on 4-hydroxy benzo hydrazide (4HBH) and its newly designed derivative [(E)–N′-((1H-Pyrrol-2-YL)methylene) –4-hydroxy benzo hydrazide and its isomers (I, II and III)] (potential inhibitors) for COVID-19 protease

Studies have shown that hydrazides and thier derivatives are used for pharmaceutical and medicinal purposes. At present, the whole world is suffering for COVID-19 virus. There are some vaccines or medicines available to treat this disease all over the world. Today the one fourth of the world’s population is under lockdown condition. In this scenario, scientists from the whole world are doing different types of research on this disease. Being a molecular modeller, this inspires us to design new types of species (may be drugs) which may be capable for COVID-19 Protease. In the present effort, we have performed docking studies of title compounds with COVID-19 protein (6LU7) for anti-COVID-19 activity. A comparative quantum chemical calculations of molecular geometries (bond lengths and bond angles) of 4-Hydroxy Benzo Hydrazide (4HBH) and its newly designed derivatve [(E)-N′-((1H-Pyrrol-2-YL)Methylene) –4-Hydroxy Benzo Hydrazide and its isomers (I, II and III)] in the ground state have also been carried out due to its biological importance and compared with the similer type of compound found in literature i.e. benzohydrazide. The optimized geometry and wavenumber of the vibrational bands of the molecules have been calculated by density functional theory (DFT) using Becke’s three-parameters hybrid functional (B3LYP/CAM-B3LYP) with 6–311G (d, p) as the basis set. Vibrational wavenumbers are compared with the observed FT-IR and FTRaman spectra of 4-Hydroxy Benzo Hydrazide. TDDFT calculations are also done on the same level of theory and a theoretical UV-vis spectrum of title molecules are also drawn. HOMO-LUMO analysis has been done to describe the way the molecule interacts with other species. Natural bond orbitals (NBO) analysis has been carried out to inspect the intra- and inter- molecular hydrogen-bonding, conjugative and hyper conjugative interactions and their second order stabilization energy. Nonlinear optical (NLO) analysis has been performed to study the non-linear optical properties of the molecule by computing the first hyperpolarizability. The variation of thermodynamic properties with temperature has been studied. QATIM analysis shows that hydrogen bonding occurs in 4HBH, isomer II and III respectively.

Spectroscopic Studies (FT-IR, FT-Raman and UV-Vis), NBO Analysis, HOMO-LUMO, First Order Hyperpolarizability and Docking Studies of 4-[4-(Bromo-Phenylimino)-Methyl]-2-Ethoxy Phenol

The FT-IR, FT-Raman and UV-Vis spectra of 4-[4-(bromo-phenylimino)-methyl]-2-ethoxy phenol (4BPMEP) were recorded and analyzed. The optimized geometrical parameters were calculated. The total energy distribution (TED) analysis was used to find the complete vibrational assignments. The UV-Vis spectra were recorded and analyzed. The hyper conjugative interaction energy E(2) and donor (i), acceptor (j) electron densities (EDs) were calculated by natural bond orbital (NBO) analysis. The band gap energy of 4BPMEP was calculated by highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) analysis. The electronic transition was studied by UV-Vis analysis of 4BPMEP with B3LYP/6-311++G(d,p) level of basis set. The non - linear optical (NLO) behavior, molecular electrostatic potential (MEP) and thermodynamic properties were also calculated. In addition, Gauge invariant atomic orbital (GIAO) method was used to calculate 1H and 13C NMR chemical shift values of 4BPMEP in the ground state at B3LYP/6-311++G(d,p) basis set. To establish the information about interactions between topoisomerase DNA gyrase enzymes and the novel compound, docking studies were carried out by Schrödinger software.

Effects of Ce3+/Dy3+ and Ce3+/Sm3+ co-doping as a luminescent modifier in alumina-borophosphate glasses for w-LED application

Ce3+/Dy3+ and Ce3+/Sm3+ co-doped alumino-borophosphate glasses (CDABP/ CSABP) were prepared and characterized for luminescence and SHG efficiency properties. FT-IR and FT-Raman spectra have been utilized to identify different functional groups of Phosphate networks. Various optical properties such as, optical absorption, optical band gap energy (Eg), Urbach energy (ΔE) and linear refractive index (n) of the glasses were determined using UV–Vis spectrometer in the spectral range 200–1200 nm. Scanning Electron Microscopy/Energy Dispersive spectrometry (SEM/EDS) reveals information about the elemental compositional homogeneity as well as the surface morphology of the prepared glasses. Influences of a luminescence co-activator of Ce3+/Dy3+ and Ce3+/Sm3+ ions in alumina-borophosphate glasses were interpreted under the excitation wavelength of 300 nm. Two emission peaks detected at 426 nm (blue) and 574 nm (Yellow) in CDABP glass corresponding to the Dy3+, whereas three emission peaks traced at 558 nm (green), 598 nm (orange) and 652 nm, (red) in CSABP glass corresponding to the Sm3+. The Influence of internal and external quantum efficiency (QE) on the glass’s photoluminescence spectrum was measured. The CIE chromaticity obtained from the luminescence spectra, confirming that the CSABP glass emits white light. The colour purity (Pc) and excitation purity (Pe) of the glasses were investigated in order to quantify the quality of light emitted by them. The second harmonic generation (SHG) efficiency of the synthesized glasses was determined without the need of a thermal polling mechanism, and the magnitude was compared to that of Urea and KDP crystal reference samples.

Synthesis, Structural Characterizations, and Quantum Chemical Investigations on 1-(3-Methoxy-phenyl)-3-naphthalen-1-yl-propenone.

In the present study, 1-(3-methoxy-phenyl)-3-naphthalen-1-yl-propenone (MPNP) is synthesized and characterized by several experimental techniques such as Fourier transform-infrared spectroscopy (FT-IR), FT-Raman, NMR and UV–vis spectral methods. The similar techniques are also investigated by the computational method using Gaussian software. The density functional theory (DFT) method is used to obtain the optimized structure using the B3LYP/6-311++G(d,p) basis set. This optimization procedure of the molecule gives the minimum energy confirmation of the structure. The computed geometrical parameters are compared with experimental data. The experimental FT-IR and FT-Raman spectra of MPNP are obtained in the regions 4000–400 and 4000–50 cm–1 respectively. The detailed vibrational assignments of the molecule are obtained with the support of potential energy distribution. The theoretical NMR (1H and 13C) analysis is conducted by the GIAO method for its structural characterization and compared with experimental chemical shifts. The experimental UV–vis spectrum is obtained in the dimethyl sulfoxide solvent and compared with the theoretically computed spectrum by the time-dependent DFT method. In addition to these studies, other analyses such as nonlinear optical, natural bonds orbital, frontier molecular orbital, molecular electrostatic potential, and NCI have been conducted to understand the nature of the molecule. The title molecule is docked and also the drug-likeness, ADMET studies were carried out. The RBD domain bound to the ACE2 receptor during the fusion makes spike glycoprotein an elusive therapeutic target in SARS-CoV-2 infection.

Synthesis, crystal structure, hirshfeld surface analysis, spectral and quantum chemical studies of pharmaceutical cocrystals of a bronchodilator drug (Theophylline)

Co-crystals of Theophylline Resorcinol monohydrate (THR) and Theophylline Pyrogallol monohydrate (THPY) have been crystallized and their molecular structures were determined by single crystal X-ray diffraction analysis. The molecular packing of THR is closely packed than THPY which influence the structure stability. The molecular geometry was optimized theoretically using Hartree-Fock (HF) and Density Functional Theory (DFT) methods. The OH-group in resorcinol is hydrogen bonded to theophylline forming a dimer ring R22(7) motif through NH···O and CH···O hydrogen bonding network which lies in the hydrophilic region. However, in THPY two bifurcated ring R21(6) and R21(5) motifs contribute greatly in constructing the crystal structure. The FT-IR and FT-Raman spectra of THR and THPY in crystalline state have been interpreted and the assignments agrees well with the calculated spectra. The solubility study is carried out to improve the pharmaceutical property of the drug. The assessment of intermolecular contacts and the interactions were quantified by Hirshfeld surface analysis and natural bonding orbital (NBO) analysis respectively. Besides, the Mulliken charge analysis and HOMO-LUMO analysis of the compounds were investigated by theoretical calculations. Antibacterial activity of THPY have shown good inhibition on pathogenic strains compared to its parent compound and therefore can be recommended to treat infections from Streptococcus pneumoniae.

Dithiane Based Boronic Acid as a Carbohydrate Sensor in an Aqueous Solution at pH 7.5: Theoretical and Experimental Approach.

Carbohydrate sensing in an aqueous solution remains a very challenging area of interest. Using the idea of covalent reversible interaction between boronic acids and the diol groups in carbohydrates enable us to design a carbohydrate sensor 1-thianthrenylboronic acid (1T), which has high selectivity towards fructose. To elucidate the sensing and binding properties of 1T with sugars, we have incorporated theoretical (DFT and TD-DFT) and spectroscopic techniques. For an optimized geometry, the complete vibrational assignments were done with FT-IR and FT-Raman spectra. Physiochemical parameters were obtained by implementing frontier molecular orbital (FMO) analysis. Further, excited state properties were determined by performing TD-DFT calculations in solvent and these properties were in good agreement with the experiment. The steady state fluorescence measurements with varying concentration of sugars, revealed that the fluorescence intensity of boronic acid is enhanced by studied sugars due to the structural modification. We also noticed remarkable changes in fluorescence lifetimes and quantum yield after adding sugars. The article also reports influence of pH on boronic acid's fluorescence intensity with and without sugars. The fluorescence of boronic acid increases with the increase in pH. These changes are due to acid-base equilibrium of boronic acid and led us to estimate the pKa value of 7.6. All the theoretical and experimental evidences suggested that 1T can be used as a possible fluorescent sensor for fructose. In addition, 1T showed very good affinity for Cu2+ ion with Ka = 150 × 102M-1, which suggests that 1T can also be used as a chemosensor for Cu2+ ions.

Evaluation of electronic properties in different solvents, spectroscopic exposition (FT-IR, FT-Raman), and molecular docking studies of 5-Chloro-2-hydroxypyridine - insulysin inhibitor

In the current work, the experimental and theoretical reports on the upgraded geometrical structure, electronic and vibrational features of 5-chloro-2-hydroxypyridine are presented assigning B3LYP method with 6–311++G (d, p) basis set. The FT-IR and FT-Raman spectra of the heading compound were documented and the geometric parameters and wavenumbers were obtained and with scaled quantum mechanics, comprehensive vibrational assignments of wavenumbers using Potential Energy Distribution (PED) were evaluated. NBO studies was used to calculate the interaction energy and electron densities of donor and acceptor bonds. Various solvents were used to find HOMO-LUMO orbitals and band gap energy. Molecular Electrostatic Potential (MEP), Fukui functions, Mulliken charges, Electron Localisation Function (ELF) and Localised Orbital Locator (LOL) of the heading molecule were also inspected. Using the TD-DFT method and a number of solutions, the UV–Visible spectrum was explored. Additionally, drug likeness, environmental toxicity properties were analysed and molecular docking was accomplished so as to recognize the hydrogen bond lengths and minimum binding energy was determined.

Essential oils loaded-chitosan nanocapsules incorporation in biodegradable starch films: A strategy to improve fruits shelf life

Thermoplastic starch (TPS) films filled with chitosan nanocapsules (CN) containing essential oils (EO) were prepared aiming active packaging. Two different EOs were studied: Ho wood (H) and Cinnamon (C). Besides, different capsules concentrations were investigated (1, 3, and 5 wt%), and the films were evaluated by chemical structure, thermal stability, crystallinity, water vapor permeability, antimicrobial assays, and potential application for strawberry packaging. The TPS/CN-Ho wood films showed a strong interaction between chitosan-starch, mainly for 3 and 5 wt%, confirmed by XRD. The FT-Raman spectra of TPS/CN-Cinnamon film indicated that Cinnamon EO quickly migrated to starch films, probably due to the new crystal structure, named C-type, affecting the film's water permeability. The addition of 1 and 3 wt% CN loaded with Ho wood or Cinnamon EO to the films decreased the water permeability. 3 wt% CN was the optimum concentration to inhibit the Escherichia coli or Bacillus subtillis growth on the films, confirming their biological activity. The films' preservation properties were evaluated using strawberries, and films with 1 or 3 wt% loaded-CN could extend the strawberries' shelf life without fungi contamination. The developed TPS films can be used as active food packaging or other films for biomedical or pharmaceutical applications.

Structure Conformation, Vibrational Properties, NLO Activity, HOMO-LUMO and Thermodynamic Parameters of Dinicotinic Acid Using Experimental and Theoretical Approach

In the present study, the Dinicotinic acid was characterized by FTIR and FT-Raman spectra in the range of 4000-450 and 4000-50 cm-1. The most stable molecular structure and optimized geometrical parameters are calculated using DFT studies. Normal Co-ordinate Analysis (NCA) was studied out by solving Inverse Vibrational Problem using 74-valence force field calculations using overlay least square technique. It reproduces into 35 fundamental frequencies with an rms error of 9.28 cm-1 in the zero-order calculations. Based on PED, vibrational modes are assigned for this molecule. The energy of HOMO & LUMO, NLO parameters, and thermodynamic parameters were computed.

Synthesis and DFT computations on structural, electronic and vibrational spectra, RDG analysis and molecular docking of novel Anti COVID-19 molecule 3, 5 Dimethyl Pyrazolium 3, 5 Dichloro Salicylate

Prospective Anti-viral compound 3, 5 Dimethyl Pyrazolium 3, 5 Dichloro Salicylate (DPDS) was synthesized and characterized using FT-IR, FT-Raman, UV and NMR spectra. To escort the experimental results, computational methods were performed using B3LYP with 6-311G (d, p) basis set expending Gaussian09w package to attain geometry of the molecule. Vibrational assignments for all the vibrational modes have been made of PED results obtained from SQM method. On contrary, FMO analysis, global chemical reactivity descriptors, Aromaticity and Natural charge analysis were studied. Molecular stability and bond strength have been inquired by executing NBO analysis. Topological features of DPDS were intended by MEP, ELF and LOL maps. UV–vis spectrum was predicted by TD-DFT method in gaseous phase and compared with the experimental spectrum for displaying the involved electronic transitions in the compound. The interactions within the DPDS molecule were investigated via RDG analysis. Molecular docking was performed with SARS-CoV-2 proteins and docking parameters were obtained. Drug likeness was carried out based on Lipinski's rule of five and the ADMET factors were also predicted.