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Structural and spectroscopic studies on fullerene and bromofullerene molecules were investigated. The reaction with liquid bromine was used to prepare bromofullerene and it was characterized by using X-ray diffraction, ultraviolet–visible, Fourier transform infrared, Fourier transform Raman, electron paramagnetic resonance, scanning electron microscopy, high resolution transmission electron and energy dispersive X-ray techniques. The XRD pattern of bromofullerene confirms the attachment of bromine to fullerene. FT-IR and FT-Raman characterization reveal the C-Br vibrations in the brominated fullerene which confirms the bromination. UV–Vis spectral analysis endorses shifting of absorption peak. EPR line width, with g-factor values, indicates the magnetic ion sites in the samples. Scanning electron microscope and high resolution transmission electron microscope signify the changes in surface and particle size of the molecule. The particle size was calculated from Debey-Sherrer's formula and corroborated by TEM images. Energy dispersive X-ray elemental micro analysis confirms the presence of bromine element in the molecule. The enhanced reactivity by substitution of bromine paves the way for designing the bioactive molecules which will be useful in the field of carbon nano-medicine and targeted drug delivery applications.

In this paper, a complete theoretical investigation of hydroxylic indole-3-pyruvic acid (HIPyA) molecule was performed using the DFT quantum chemical, molecular docking and molecular dynamics calculations. The conformational analysis of HIPyA molecule was carried out using density functional theory quantum chemical calculations. The most stable structure of the studied molecule was predicted by means of DFT/B3LYP method with cc-pVTZ basis set. The simulated vibrational frequencies were assigned and proved to be in agreement with the available experimental FT-IR data. The effects of gas phase and solvents on UV-visible spectra of HIPyA molecule were simulated using TD-DFT/B3LYP method with cc-pVTZ basis set. The analysis of the density of states spectrum validates the frontier molecular orbitals results, which reveals the charge transfer interaction in HIPyA molecule. The molecular electrostatic potential surface confirms the electrophilic and nucleophilic reactive sites of the studied molecule. The natural bond orbital analysis evidences the bioactivity of the studied molecule. The obtained first order hyperpolarizability value is 33.596 times greater than urea, which confirms the nonlinear optical activity of HIPyA molecule. The molecular docking analysis reveals that the studied molecule under interest can act as a potent inhibitor against the amyloid β-protein (Aβ) enzyme, which causes the Alzheimer’s disease. The molecular dynamics analysis confirms the reliability of the docking results. Communicated by Ramaswamy H. Sarma

This study focuses on the effects of the bromine atom on the molecular structure parameters in the main tautomeric forms of 5-bromouracil (5BrU), and as well, its effect on hydration and on the Watson-Crick (WC) pairs as compared to uracil molecule. The influence of the bromine atom was studied in several environments. The hydration effect on the molecular structure and energies of the main tautomeric forms of 5BrU was analyzed by considering a variable number of water molecules in explicit form up to 30 to simulate the first and second hydration shells. The ‘mutagenic’ 2-hydroxy-4-oxo (U2) enol tautomer of 5BrU, but not of uracil, was absolutely favored over the keto form in clusters with more than 20 water molecules. For all calculations, B3LYP and M06-2X Methods were used. The effect of the bromine atom when it was inserted into the natural and reverse WC pairs uridine-adenosine was also determined, and counterpoise (CP) corrected interaction energies were calculated. The effect of the bromine atom was analyzed in several DNA:RNA hybrid microhelices. Different backbone and helical parameters were calculated and compared. The bromine atom destabilizes its base pair, with a remarkable increase in the rise parameter (Dz) corresponding to the microhelix, and to a slight increase in the diameter (d). Molecular docking calculations were also carried out with 5BrU for targeted proteins associated with diabetes, hepatocellular carcinoma and breast and lung cancers. The molecular docking analysis confirms that the 5BrU molecule may play an important role as a promising inhibitor against breast cancer. Communicated by Ramaswamy H. Sarma

Environmental research has the objective of finding solutions to environmental degradation. To this aim, an optimized solid bio-polymer electrolyte (BPE) based on cellulose acetate (CA) with lithium nitrate (LiNO3) has been developed to achieve the possible energy storage Li-ion batteries. CA is one of the natural polymers with very good film forming capacity. The widespread use of CA is attributed to the availability of renewable resources, non-toxic nature, low cost, and bio-compatible material. Here, we demonstrate an extremely simplest process of solution-casting technique for the development of BPE by incorporating various LiNO3 compositions (wt.%) with bio-polymer material CA. The crystalline nature of the CA with LiNO3 has been analyzed by X-ray diffraction (XRD) measurement. The bio-polymer-salt complex formation and the biopolymer-proton interactions have been investigated through Fourier transform infrared (FTIR) spectroscopy. Electrochemical impedance spectroscopy has been used to examine the ionic conductivity of the BPEs at room temperature (303 K). The highest ionic conductivity of 1.93 × 10−3S/cm has been achieved for 50CA/50LiNO3 polymer electrolyte. Electrochemical studies show that highest BPE has high electrochemical stability windows. The conducting species is found to be Li+ ion, which has been confirmed by transference number measurement (TNM). Primary lithium battery with discharge profile has been constructed for 50CA/50LiNO3. This research will help to identify a new lithium ion membrane for battery technology and other electrochemical device applications.

In this present work, the solution casting technique was utilized to develop the proton conducting solid biopolymer electrolyte by the complex formation of cellulose acetate (CA) with the ammonium thiocyanate (NH4SCN) salt. The crystalline nature and complex formation of CA with different concentrations of NH4SCN were investigated using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic techniques. The XRD analysis revealed that the amorphous natures of the CA complex were increased with increase of NH4SCN salt concentration, which leads to the higher ionic conductivity. The FTIR analysis confirmed the complex formation between CA and salt matrix. Differential scanning calorimetry (DSC) was used to predict the glass transition temperature (Tg) values, which reveals that the Tg value increase with respect to the increase of NH4SCN concentration. The electrical conductivity was measured using AC impedance analyzer, which showed that the magnitude of ionic conductivity increases with an increase in salt concentration up to 50CA:50NH4SCN. The 50CA:50NH4SCN has maximum ionic conductivity value of 3.31 × 10−3 S cm−1. Transference number measurement was carried out to investigate the nature of the charge transport species in the polymer electrolyte. The proton battery was constructed with the highest conducting polymer electrolyte 50CA:50NH4SCN and its open circuit voltage with load were studied. Hence, the present investigation paves the way for the development of fuel cell and primary proton battery applications.

Conformational and molecular docking analysis of 2-acetylamino-5-bromo-6-methylpyridine molecule was carried out and the vibrational spectral analysis was also carried out using experimental and theoretical methods. The calculated and experimentally observed vibrational frequencies of the molecule were assigned and compared. The pyridine ring CH stretching and CH3 stretching vibrational modes were shifted towards higher wavenumber (blue shift). The C=O stretching vibrational frequency was shifted towards lower wavenumber (red shift). Ultraviolet-visible spectrum of the molecule simulated theoretically was further validated experimentally. Molecular reactivity and stability were investigated using the frontier molecular orbital analysis and the related quantum chemical molecular properties. Natural bond orbital analysis and the structure activity relations were also studied to confirm the bioactivity of the molecule. Anticancer activity was examined based on molecular docking analysis and it has been identified that the AABMP molecule can act as a good inhibitor against lung cancer.

Influence of N-Methylaniline (NMA) on the physicochemical and optical properties of γ-Al2O3 nanoparticles were investigated using XRD, FTIR, UV-Vis DRS, TEM, AFM, PL, TGA and the results were reported here. The TEM results were showed that the surface morphology of NMA capped γ-Al2O3 nanoparticles has sphere like nanostructures. The size of the nanoparticles was controlled by the concentration of NMA and thus modified the geometry of γ-Al2O3 nanoparticles from primary (~8 nm) to spherical nanoparticles (~30-50 nm). XRD results were confirmed the enhancement of crystallite size of γ-Al2O3 proportionally with the NMA molar concentration. FTIR results were confirmed the formation of NMA capped γ-Al2O3nanospheres by N-H stretching and O-H bending vibrations. The PL results were indicated that, the emission intensities at 589 nm (yellow emission) and 713 nm (orange-red emission) were reduced after the capping of NMA for the defects F_2^(2+ )center and non-bridging oxygen hole center (NBOHC).

The conformational analysis of 2-amino-6-methoxy-3-nitropyridine molecule (AMNP) has been carried out using density functional theory calculations. The vibrational spectra of the molecule is simulated theoretically and compared experimentally, and the vibrational frequencies are assigned on the basis of potential energy distribution calculations. Electronic properties of the molecule derived from the theoretical ultraviolet–visible spectrum are validated experimentally. The higher non-linear optical activity of the molecule is indicated in the first-order hyperpolarizability calculations. The natural bond orbital and Mulliken atomic charge distribution analysis confirm intramolecular charge transfers and intramolecular interactions. The Frontier molecular orbitals are plotted, and the related molecular properties are calculated and discussed. The molecular electrostatic potential contour map is simulated. As the presence of intramolecular interactions and the associated charge transfers between the pyridine ring of AMNP molecule and the lone pair of oxygen is a common molecular feature of a pharmaceutical compound, this investigation paves the way for its possible biomedical applications. Further, the considerably higher non-linear optical (NLO) activity of the molecule identified suggests its potential applications in the design of new optical materials.

CuO thin films were deposited onto glass substrates using Chemical bath deposition technique by varying the pH of the solution. Structural, optical and electrical properties of the synthesized films were studied as a function of the solution pH. X-ray diffractometry, scanning electron microscopy, UV–Vis spectroscopy and Hall effect measurements were used to explore the structure, morphology, optical and electrical properties of the films, respectively. All the films have exhibited orthorhombic structure with preferential orientation along the (111) plane. X-ray line profile analysis has been carried out to determine the microstructural parameters such as crystallite size, RMS microstrain, dislocation density and stacking fault probability. Morphological studies have revealed that the uniformity of the film surface, and the average particle size was found to increase with solution pH. Optical parameters such as band gap, refractive index, extinction coefficient, real and imaginary dielectric constants and optical conductivity have been estimated from optical absorption measurements. Carrier concentration and mobility of charge carriers estimated from the Hall measurement were found to be 7.43 × 1013 cm−3 and 11.84 cm2 V−1 s−1 respectively for CuO films prepared at solution pH 11.0.

We present a theoretical study on shallow donor binding energies of CdS/ CdZnS nano dot as a strength of applied magnetic field along Z direction for various Zn concentration. Calculations are carried out by using the technique of variational ansatz within the frame work of effective mass approximation. Our results show that the binding energies are drastically affected by the dot radius, the strength of magnetic field and concentrations.

Silver nanoparticles were synthesized using solution combustion method with citric acid as fuel. The prepared silver nanoparticles exhibit fcc crystalline structure with particle size of ~50 nm. The morphology and purity of the silver nanoparticles were also studied by high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray analysis (EDX). Surface-enhanced Raman scattering (SERS) spectra of 2,6-dicarbethoxy-3,5-bis(pyridine-3-yl)tetrahydro-1,4-thiazine-1,1-dioxide (DBTD) adsorbed on silver nanoparticles were investigated. Orientation of DBTD on silver nanoparticles has been inferred from normal Raman spectrum (nRs) and SERS spectral feature. The observed spectral feature evidenced that DBTD would adsorb on silver surface with tilted orientation through the lone pair electrons of C–N, C=O, S=O, and pyridine ring. The present investigation has been a model system to deduce the interaction of drugs with DNA.

Surface-enhanced Raman scattering (SERS) studies of 2-trifluoroacetylpyrrole (TFAP) molecule adsorbed on synthesized colloidal silver nanoparticles (SNPs) and gold nanoparticles (GNPs) were reported and compared to the normal Raman spectra (nRs) of TFAP molecule in solid and liquid states. The experimental results were validated with the simulated nRs and SERS spectra of the molecule using density functional theory (DFT) calculations. The structures of the TFAP, TFAP-Ag3 and TFAP-Au4 molecular systems were optimized at different level of basis sets. HR-TEM analysis reveals that the colloidal SNPs and GNPs were monodispersed in spherical shape with average particle size were predicted as ~20 and ~25 nm, respectively. The observed red shift and decreased intensity behavior in the UV–visible spectral analysis confirm that the TFAP molecule chemisorbed on the colloidal SNPs and GNPs surface. Frontier molecular orbitals (FMOs) analysis points out the charge transfer from silver cluster to molecule and gold cluster to molecule in the TFAP-Ag3 and TFAP-Au4 molecular systems, respectively. The molecular electrostatic potential surface and Fukui functions analysis further validated the charge transfer interaction in the molecular systems. SERS spectral analysis confirms that the TFAP molecule was adsorbed on colloidal SNPs and GNPs surface with tilted orientation through the lone pair electrons on oxygen atom in the C O group, pyrrole ring π electrons and lone pair electrons on fluorine atom in the trifluoro group. Moreover, the calculated SERS enhancement factor values indicate that the title molecule chemisorbed on colloidal GNPs surface with higher affinity than that of colloidal SNPs surface. Hence, the present study paves the way for the designing of SERS active colloidal silver and gold substrates, which will be useful for the development of pyrrole related biosensors.

The conformational analysis was carried out to predict the most stable, optimized structure of 2-hydroxy-3,5-dinitropyridine among various conformers. The most stable, optimized structure of the molecule was predicted by the density functional theory (DFT) using the B3LYP method with the cc-pVQZ basis set. The vibrational frequencies, natural atomic charge distribution, and thermodynamic properties were calculated. The molecular electrostatic potential surface and contour map were simulated. The experimental and theoretical vibrational frequencies were assigned on the basis of potential energy distribution calculation. The density of states (DOS) spectrum was simulated. The frontier molecular orbital analysis was carried out. The natural bond orbital (NBO) analysis was performed to evaluate the donor–acceptor interactions in the molecule. The structure–activity descriptors were determined by Fukui functions and local reactivity descriptor calculations. The nonlinear optical (NLO) activity of the molecule was studied. The second harmonic generation test confirms the NLO activity of the title molecule.

The conformational analysis was carried out to predict the most stable, optimized structure of the 2-hydroxy-3,5-dinitropyridine among various conformers. The most stable, optimized structure of the molecule was predicted by the density functional theory using the B3LYP method with cc-pVQZ basis set. The vibrational frequencies, natural atomic charge distribution and thermodynamic properties were calculated. The molecular electrostatic potential surface and contour map were simulated. The experimental and theoretical vibrational frequencies were assigned on the basis of potential energy distribution calculation. The density of states spectrum was simulated. The frontier molecular orbitals analysis was carried out. The natural bond orbital analysis was performed to evaluate the donor-acceptor interactions in the molecule. The structure-activity descriptors were determined by Fukui functions and local reactivity descriptors calculations. The nonlinear optical activity of the molecule was studied. The second harmonic generation test confirms the nonlinear optical activity of the title molecule.

Electron spin resonance spectroscopy (ESR) studies on the reduction process of nitroxyl spin probes were carried out for 1mM concentration of 14N-labeled pyrrolidine nitroxyl spin probes, 3-carbamoyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (carbamoyl-PROXYL) and 3-carboxy-2,2,5,5-tetramethyl-pyrrolidine -1-oxyl (carboxy-PROXYL), 14N-labeled piperidine nitroxyl spin probes, 4-methoxy-2,2,6,6-tetramethyl-piperidine-1-oxyl (methoxy-TEMPO) and 4-acetamido-2,2,6,6-tetramethyl-piperidine-1-oxyl (acetamido-TEMPO) in 1 mM concentration of ascorbic acid as a function of time. The half-life time and decay rate were estimated. The piperidine nitroxyl spin probes show a short half-life time compared with that of pyrrolidine nitroxyl spin probes. This result indicates that the higher stability of pyrrolidine nitroxyl spin probes. The ESR was also recorded for 1mM concentration of pyrrolidine nitroxyl spin probes and piperidine nitroxyl spin probes in pure water using X-band ESR spectrometer. The ESR parameters such as line width, hyperfine coupling constant, g-factor, signal intensity ratio and rotational correlation time were determined. These results indicate that the pyrrolidine nitroxyl spin probes have narrow line width and fast tumbling compared with the piperidine nitroxyl spin probes. Therefore, this study reveals that the pyrrolidine nitroxyl spin probes can act as good redox sensitive spin probes for free radical imaging.

Single crystals of triglycine sulphate (TGS) doped with L-histidine and aniline were studied by Raman Spectroscopy. The structure and symmetry of molecules, the nature of bonding and the effect of crystalline field on molecular vibrations were studied for pure and doped TGS. The characteristic group frequencies were identified and analysed for H2SO4 and glycine. The skeletal motion, lattice vibrational peaks were observed in the low wavenumber region. The site symmetry effect and the correlation field effect were studied from the splitting of vibrational bands. The observed Raman shift towards higher wave number region reveals that the symmetry reduction in doped TGS crystals. The broadening of Raman spectral line showed that a decrease in the hardness value for the doped crystals. Comparative studies of the Raman Spectra of pure TGS and doped TGS were also carried out.

Electron spin resonance (ESR) spectroscopy studies on the reduction process of nitroxyl radicals were carried out for 1mM concentration of 14N-labeled nitroxyl radicals in 1 mM concentration of ascorbic acid as a function of time. The half life time and decay rate were estimated for 1mM concentration of 14N labeled nitroxyl radicals in 1 mM concentration of ascorbic acid. From the results, the increase in half life time and decrease in decay rate were calculated for TEMPONE compared with TEMPO and TEMPOL radicals, which indicates the higher stability of TEMPONE radical. The observed radical scavenging activity is also higher for TEMPONE radical. The ESR spectrum was also recorded for 1mM concentration of 14N-labeled nitroxyl radicals in pure water and the ESR parameters, line width, hyperfine coupling constant, g-factor, signal intensity ratio and rotational correlation time were obtained. These results indicate that the TEMPONE radical has narrowest line width and fast tumbling motion compared with TEMPO and TEMPOL. Therefore, this study reveals that the TEMPONE radical can act as a good redox sensitive spin probe for molecular imaging.