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The theoretical calculations of the 2,4-dimethoxy-1,3,5-triazine (DMT) molecule were performed with the help of density functional theory (DFT) calculations using 6-311++G(d,p) basis set. The confo...

Strontium carbonate (SrCO3) nanostructures with different morphology from bundles of nanorods to branchlet-like were synthesized by a simple and cost effective wet chemical method. Surface of nanoparticles capped by the adsorption of surface modifying agents is known for strongly influence the physicochemical properties. Therefore, in this contribution, the effect of well-established capping agent triethylamine (TEA) on the morphology of SrCO3 has been investigated. The effect of TEA on morphology and the size of the particles have been evaluated by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analyses. As increase in the concentration of TEA lead to the formation of branchlet-like morphology. The as prepared samples were extensively characterized by various spectroscopic techniques such as Fourier transform infrared spectroscopy (FTIR) and Raman. To gain further information on the electronic states of nanostructure, X-ray photoelectron spectroscopy (XPS) analysis was carried out, which showed that peaks shift in the electronic state of Sr at higher concentration of TEA. This study thus led to a better understanding of evaluation of organic matter on the morphology of SrCO3 nanostructure.

The molecular structure of the 1,4-Bis(methylamino)anthraquinone molecule was optimized by the DFT/B3LYP method with 6-311G++(d,p) basis set using Gaussian 09 program. The vibrational frequencies were assigned on the basis of potential energy distribution calculation using VEDA 4.0 program. The 1H and13C NMR isotropic chemical shift values of the molecule were calculated using Gauge-Invariant-atomic orbital method in DMSO solution. The UV-Visible spectrum of the molecule was simulated by the time dependent-DFT/B3LYP method associated with the polarizable continuum model using 6-31G++ (d.p) basis set using ethanol as the solvent. The molecular reactivity and kinetic stability of the molecule were confirmed using frontier molecular orbitals analysis. The Mulliken atomic charge distribution values of the molecule were calculated. The natural bond orbital analysis was performed to evaluate the donor-acceptor interactions within the molecule. The molecular docking analysis confirms that the title molecule acts as a good inhibitor of the protein kinase CK2, which is used as a molecular target in a preclinical in vitro model of pancreatic cancer. Hence, the present study paves the way for designing the novel drugs for the treatment of pancreatic cancer.

Wastewater effluents from textile industries contain toxic chemicals, which need to be treated prior to effluent disposal. Semiconductor photocatalysis is emerging as potential technique for treating such effluents. The main advantage of this technique is the fact that organic contaminants are completely mineralized without requiring any further treatment. Titanium dioxide (TiO2) is the most efficient semiconductor photocatalyst as it is stable in aqueous media and tolerant to both alkaline and acidic solutions. Due to its wide bandgap (Eg ≈ 3.0 eV), TiO2 can absorb only the light in the UV region, and that is one of the biggest drawbacks of TiO2. Several attempts have been made recently to improve the photocatalytic performances of a TiO2 photocatalyst by extending the photoresponse of the UV-active semiconductor into the visible region through the bandgap engineering. This chapter outlines the interaction of fluorine and carbon nanotubes in TiO2 structure and the changes in photocatalytic activity of TiO2 and multiwalled carbon nanotube-fluorine-codoped TiO2 nanocomposites, which find potential applications of the nanocomposite in water treatment.

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

In this study, the effect of immersion time of the substrate in the chemical deposition bath on the physical properties of cupric oxide films is estimated by varying the immersion time as 15, 30, 4...

Adsorption behaviour of iminodiacetic acid (IDA) on silver surface were investigated based on surface enhanced Raman spectroscopy (SERS) technique and density functional theory calculations. The si...

Potential energy surface scan was performed and the most stable molecular structure of the N , N -di- tert -butoxycarbonyl (Boc)-2-amino pyridine (DBAP) molecule was predicted. The most stable molecular structure of the molecule was optimized using B3LYP method with cc-pVTZ basis set. Anticancer activity of the DBAP molecule was evaluated by molecular docking analysis. The structural parameters and vibrational wavenumbers were calculated for the optimized molecular structure. The experimental and theoretical wavenumbers were assigned and compared. Ultraviolet–Visible spectrum was simulated and validated experimentally. The molecular electrostatic potential surface was simulated and Fukui function calculations were also carried out to investigate the reactive nature of the DBAP molecule. The natural bond orbital analysis was also performed to probe the intramolecular interactions and confirm the bioactivity of the DBAP molecule. The molecular docking analysis reveals the better inhibitory nature of the DBAP molecule against the epidermal growth factor receptor ( EGFR ) protein which causes lung cancer. Hence, the present study unveils the structural and bioactive nature of the title molecule. The DBAP molecule was identified as a potential inhibitor against the lung cancer which may be useful in further development of drug designing in the treatment of lung cancer.

Agarose is a tissue-equivalent material and its imaging characteristics similar to those of real tissues. Hence, the dynamic nuclear polarization studies of 3-carboxy-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (carboxy-PROXYL) in agarose gel were carried out. The dynamic nuclear polarization parameters such as spin lattice relaxation time, longitudinal relaxivity, leakage factor, saturation parameter and coupling parameter were estimated for 2 mM carboxy-PROXYL in phosphate-buffered saline solution and water/agarose mixture (99 : 1). From these results, the spin probe concentration was optimized as 2 mM, and the reduction in enhancement was observed for carboxy-PROXYL in water/agarose mixture (99 : 1) compared with phosphate-buffered saline solution. Phantom imaging was also performed with 2 mM concentration of carboxy-PROXYL in various concentrations of agarose gel at various radio frequency power levels. The results from the dynamic nuclear polarization measurements agree well with the phantom imaging results. These results pave the way for designing model system for human tissues suited to the biological applications of electron spin resonance/Overhauser-enhanced magnetic resonance imaging.

Detailed dynamic nuclear polarization and electron spin resonance studies were carried out for 3-carbamoyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl, 3-carboxy-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl,3-methoxycarbonyl-2,2,5,5-tetramethy pyrolidine-1-oxyl nitroxyl radicals and their corresponding deuterated nitroxyl radicals, used in Overhauser-enhanced magnetic resonance imaging for the first time. The dynamic nuclear polarization parameters such as DNP factor, longitudinal relaxivity, saturation parameter, leakage factor and coupling factor were estimated for deuterated nitroxyl radicals. DNP enhancement increases with agent concentration up to 3 mM and decreases above 3 mM. The proton spin-lattice relaxation time and the longitudinal relaxivity parameters were estimated. The leakage factor increases with increasing agent concentration up to 3 mM and reaches plateau in the region 3-5 mM. The coupling parameter shows the interaction between the electron and nuclear spins to be mainly dipolar in origin. DNP spectrum exhibits the FWHM values are higher for undeuterated nitroxyl radicals compared with deuterated nitroxyl radicals, which leads to the increase in DNP enhancement. The ESR parameters such as, the line width, line shape, signal intensity ratio, rotational correlation time, hyperfine coupling constant and g-factor were calculated. The narrow line width was observed for deuterated nitroxyl radicals compared with undeuterated nitroxyl radicals, which leads to the higher saturation parameter value and DNP enhancement. The novelty of the work permits clear understanding of the DNP parameters determining the higher DNP enhancement compared with the undeuterated nitroxyl radicals.

The electron spin resonance studies were carried out for 2 mm concentration of 14 N-labeled and 15 N-labeled 3-carbamoyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl, 3-carboxy-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl, 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl and their deuterated nitroxyl radicals using X-band electron spin resonance spectrometer. The electron spin resonance line shape analysis was carried out. The electron spin resonance parameters such as linewidth, Lorentzian component, signal intensity ratio, rotational correlation time, hyperfine coupling constant and g-factor were estimated. The deuterated nitroxyl radicals have narrow linewidth and an increase in Lorentzian component, compared with undeuterated nitroxyl radicals. The dynamic nuclear polarization factor was observed for all nitroxyl radicals. Upon 2 H labeling, about 70% and 40% increase in dynamic nuclear polarization factor were observed for 14 N-labeled and 15 N-labeled nitroxyl radicals, respectively. The signal intensity ratio and g-value indicate the isotropic nature of the nitroxyl radicals in pure water. Therefore, the deuterated nitroxyl radicals are suitable spin probes for in vivo/in vitro electron spin resonance and Overhauser-enhanced magnetic resonance imaging modalities. Copyright © 2017 John Wiley & Sons, Ltd.

In this work, the detailed studies of electron spin resonance (ESR) and overhauser-enhanced magnetic resonance imaging (OMRI) were carried out for permeable nitroxyl spin probe, MC-PROXYL as a function of agent concentration in liposomal solution. In order to compare the impermeable nature of nitroxyl radical, the study was also carried out only at 2 mM concentration of carboxy-PROXYL. The ESR parameters were estimated using L-band and 300 MHz ESR spectrometers. The line width broadening was measured as a function of agent concentration in liposomal solution. The estimated rotational correlation time is proportional to the agent concentration, which indicates that less mobile nature of nitroxyl spin probe in liposomal solution. The partition parameter and permeability values indicate that the diffusion of nitroxyl spin probe distribution into the lipid phase is maximum at 2 mM concentration of MC-PROXYL. The dynamic nuclear polarization (DNP) parameters such as DNP factor, longitudinal relaxivity, saturation parameter, leakage factor and coupling factor were estimated for 2 mM MC-PROXYL in 400 mM liposomal dispersion. The spin lattice relaxation time was shortened in liposomal solution, which leads to the high relaxivity. Reduction in coupling factor is due to less interaction between the electron and nuclear spins, which causes the reduction in enhancement. The leakage factor increases with increasing agent concentration. The increase in DNP enhancement was significant up to 2 mM in liposomal solution. These results paves the way for choosing optimum agent concentration and OMRI scan parameters used in intra and extra membrane water by loading the liposome vesicles with a lipid permeable nitroxyl spin probes in OMRI experiments.

Conformational analysis was carried out for N -(5-aminopyridin-2-yl)acetamide (APA) molecule. The most stable, optimized structure was predicted by the density functional theory calculations using the B3LYP functional with cc-pVQZ basis set. The optimized structural parameters and vibrational frequencies were calculated. The experimental and theoretical vibrational frequencies were assigned and compared. Ultraviolet–visible spectrum was simulated and validated experimentally. The molecular electrostatic potential surface was simulated. Frontier molecular orbitals and related molecular properties were computed, which reveals that the higher molecular reactivity and stability of the APA molecule and further density of states spectrum was simulated. The natural bond orbital analysis was also performed to confirm the bioactivity of the APA molecule. Antidiabetic activity was studied based on the molecular docking analysis and the APA molecule was identified that it can act as a good inhibitor against diabetic nephropathy.

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.

Manufacturing quantum dots (QDs) and their suspensions through incorporation of surface coatings can have enormous attention in manipulating surface properties such as size, shape, and structure. The surface of engineered QDs capped by the adsorption of organic matter is known for strongly influencing their physicochemical properties, which is very useful for many biomedical and technological applications. Prerequisite for any possible applications, the effect of organic matter on the surface of nanoparticles is important. In this contribution, owing to the privileged medicinal scaffolds based on the structure of pyridine derivatives, we have synthesized cerium oxide QDs with ∼2.4 nm in size capped with anionic-rich head groups of 2-amino-3-chloro-5-trifluoromethylpyridine (ACTP), and the assay is based on the steric stabilizing capping behavior of anionic-rich ACTP molecules on the surface of CeO2 QDs. Aggregated QDs, obtained by adding capping agent in the reaction, have been characterized by powder X-r...

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.

Stable molecular structure of N-phenyl-3-pyridinecarboxmide (Nicotinanilide) was predicted through conformational analysis and the vibrational spectral analysis was carried out using experimental and theoretical methods. The calculated and experimentally observed vibrational frequencies of the molecule were assigned and compared. The observed red shift in C O stretching vibrations confirms the mesomeric effects of the C O functional group. The n→π* and π→π* electronic transitions of the molecule were predicted from the theoretically simulated ultraviolet–visible spectra and were validated experimentally. Natural bond orbital analysis was performed to investigate the intra-molecular stabilization interactions, which are responsible for the bioactivity and the nonlinear optical property of the molecule. Molecular reactivity and the possible reactive sites of the molecule were investigated based on the frontier molecular orbitals analysis and Fukui functions respectively. The total electron density mapped with the molecular electrostatic potential surface was plotted to confirm the possible reactive sites of the molecule. The title molecule is identified to be a potential candidate for pharmaceutical 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.

Co-precipitation method has been used to synthesis δ-Al2O3 nanorods under room temperature using citric acid as a chelating agent. The effect of citric acid on the formation of δ-Al2O3 nanorods, functional properties and surface area were investigated. X-ray diffraction (XRD) results revealed that Al2O3 nanorods possess delta phase and average crystallite size was 8 nm. The characteristic vibrational frequencies observed at 632, 1413 and 3468 cm−1 corresponds to Al-O, COO− and O H respectively were confirmed by Fourier transform infrared spectroscopy (FTIR). The morphology and structure of as prepared nanomaterials were evaluated by scanning electron microscopy (SEM). The effective surface area of the prepared nanoparticles was in the range of 162–164 m2g−1. The influence of citric acid on morphology of δ-Al2O3 nanorods has been investigated by Transmission electron microscopy (TEM). The occurrence of physisorption was evaluated by Brunauer-Emmett-Teller (BET) studies. The increased ionic conductivity by the influence of citric acid was demonstrated by AC impedance analysis towards primary battery application. The above investigations have shown that the present work would help to understand the pathway to surface chemistry of nanoparticles.

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).

International audience; Silver nanoparticles (Ag NPs) were prepared by solution combustion method with urea as fuel. Silver nanoparticles were characterized by UV-visible spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Surface-enhanced Raman scattering (SERS) of 2-bromo-3-me thyl-1,4-dimethoxy-9,10-anthraquinone (BMDMAQ) adsorbed on silver nanoparticles was investigated. The orientation of BMDMAQ on silver nanoparticles was inferred from nRs and SERS spectral features. Density functional theory (DFT) calculation was also performed to study the theoretical performance. The observed spectral features such as the high intensity of C-H out-of-plane bending mode and ring C-C stretching mode revealed that BMDMAQ adsorbed on silver surface through 'stand-on' orientation. Anthraquinone (AQ) derivatives have wide biomedical application which includes laxatives, antimalarials and antineoplastics used in the treatment of cancer. This present study would help to identify the interaction of drug molecules with DNA. (C) 2015 Elsevier B.V. All rights reserved.

The dynamic nuclear polarization (DNP) studies were carried out for 15 N labeled carbamoyl-PROXYL in pure water and pure water/glycerol mixtures of different viscosities (1.8 cP, 7 cP and 14 cP). The dependence of DNP parameters was demonstrated over a range of agent concentration, viscosities, RF power levels and ESR irradiation time. DNP spectra were also recorded for 2 mM concentration of 15 N labeled carbamoyl-PROXYL in pure water and pure water/glycerol mixtures of different viscosities. The DNP factors were measured as a function of ESR irradiation time, which increases linearly up to 2 mM agent concentration in pure water and pure water/glycerol mixtures of different viscosities. The DNP factor started declining in the higher concentration region (∼3 mM), which is due to the ESR line width broadening. The water proton spin–lattice relaxation time was measured at very low Zeeman field (14.529 mT). The increased DNP factor (35%) was observed for solvent 2 ( η = 1.8 cP) compared with solvent 1 ( η = 1 cP). The increase in the DNP factor was brought about by the shortening of water proton spin–lattice relaxation time of solvent 2. The decreased DNP factors (30% and 53%) were observed for solvent 3 ( η = 7 cP) and solvent 4 ( η = 14 cP) compared with solvent 2, which is mainly due to the low value of coupling parameter in high viscous liquid samples. The longitudinal relaxivity, leakage factor and coupling parameter were estimated. The coupling parameter values reveal that the dipolar interaction as the major mechanism. The longitudinal relaxivity increases with the increasing viscosity of pure water/glycerol mixtures. The leakage factor showed an asymptotic increase with the increasing agent concentration. It is envisaged that the results reported here may provide guidelines for the design of new viscosity prone nitroxyl radicals, suited to the biological applications of DNP.

SERS provides essential data regarding the interaction of molecules in drugs with DNA. In the present study silver nanoparticles were synthesized using a solution combustion method with urea as fuel. The prepared silver nanoparticles are rod like structure. Surface-enhanced Raman scattering (SERS) of N-(1-2-bromophenyl)-2-(2-nitrophenyl)ethyl)-4-methylbenzenesulfonamide (BrS) adsorbed on the silver nanoparticle was studied. The nRs and Raman spectral analysis reveal that the BrS adsorbed tilted orientation on the silver surface. Vibrational modes of nRs along with HF calculations are also performed to study the HOMO and LUMO behavior and vibrational features of BrS.

Low-frequency electron spin resonance studies were performed for 2 mM concentration of deuterated permeable and impermeable nitroxyl spin probes, 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl and 3-carboxy-2,2,5,5,-tetramethyl-1-pyrrolidinyloxy in pure water and various concentrations of corn oil solution. The electron spin resonance parameters such as the line width, hyperfine coupling constant, g factor, rotational correlation time, permeability, and partition parameter were estimated. The broadening of line width was observed for nitroxyl radicals in corn oil mixture. The rotational correlation time increases with increasing concentration of corn oil, which indicates the less mobile nature of spin probe in corn oil mixture. The membrane permeability and partition parameter values were estimated as a function of corn oil concentration, which reveals that the nitroxyl radicals permeate equally into the aqueous phase and oil phase at the corn oil concentration of 50%. The electron spin resonance spectra demonstrate the permeable and impermeable nature of nitroxyl spin probes. From these results, the corn oil concentration was optimized as 50% for phantom studies. In this work, the corn oil and pure water mixture phantom models with various viscosities correspond to plasma membrane, and whole blood membrane with different hematocrit levels was studied for monitoring the biological characteristics and their interactions with permeable nitroxyl spin probe. These results will be useful for the development of electron spin resonance and Overhauser-enhanced magnetic resonance imaging modalities in biomedical applications.

Surface modification of multi-walled carbon nanotubes (MWCNTs) was carried out by introducing mixture of concentrated sulphuric acid and nitric acid by ultrasonication process. The pristine and surface modified MWCNTs were characterized by X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), Raman spectroscopy and Scanning electron microscopy (SEM) techniques. FT-IR spectra revealed that the presence of carboxylic acid functional groups on the surface of MWCNTs. The integrated intensity ratio of pristine and surface modified MWCNTs was calculated by Raman spectroscopic analysis. XRD patterns examines the crystallinity of the surface modified MWCNTs. SEM analysis investigates the change in morphology of the surface modified MWCNTs compared with that of pristine, which is due to the attachment of the carboxylic acid functional groups. Surface modified MWCNTs acts as precursors for further functionalization with various biomolecules, which improves the biocompatibility and initiates the implementatio...

International audience; In the present study, the silver nanoparticles were synthesized using a solution combustion method with urea as fuel. The prepared silver nanoparticles show an FCC crystalline structure with particle size of 59 nm. FESEM image shows the prepared silver is a rod like structure. The surface-enhanced Raman scattering (SERS) spectrum indicates that the N-(1-(2-chlorophenyl)-2-(2-nitrophenyl)ethyl)-4-methylbenzenesulfonamide (CS) molecule adsorbed on the silver nanoparticles. The spectral analysis reveals that the sulfonamide is adsorbed by tilted orientation on the silver surface. The Hatree Fock calculations were also performed to predict the vibrational motions of CS. This present investigation has been a model system to deduce the interaction of drugs with DNA. (C) 2014 Elsevier B.V. All rights reserved.

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.

The most stable, optimized structure of the 2-amino-3-chloro-5-trifluoromethyl pyridine (ACTP) molecule was predicted by the density functional theory calculations using the B3LYP method with cc-pVQZ basis set. Antitumor activity of the ACTP molecule was evaluated by molecular docking analysis. The structural parameters and vibrational wavenumbers were calculated for the optimized molecular structure. The experimental and theoretical vibrational wavenumbers were assigned and compared. Ultraviolet-visible spectrum was simulated and validated experimentally. The molecular electrostatic potential surface was simulated. Frontier molecular orbitals and related molecular properties were computed and further density of states spectrum was simulated. The natural bond orbital analysis was also performed to confirm the bioactivity of the ACTP molecule. The molecular docking analysis reveals the better inhibitory nature of the ACTP molecule against the colony-stimulating factor 1 (CSF1) gene which causes tenosynovial giant-cell tumor. Hence, the ACTP molecule can act as a potential inhibitor against tenosynovial giant-cell tumor.

Electron spin resonance (ESR) studies were carried out for 2mM 14N labeled 2H enriched 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) and 3–carboxy-2,2,5,5,-tetramethyl-1-pyrrolidinyloxy (carboxy-PROXYL) in pure water and various concentrations of corn oil. The ESR parameters, such as the line width, hyperfine coupling constant, g-factor, rotational correlation time, partition parameter and permeability were reported for the samples. The line width broadening was observed for both nitroxyl radicals in corn oil solutions. The partition parameter for permeable MC-PROXYL in corn oil increases with increasing concentration of corn oil, which reveals that the nitroxyl spin probe permeates into the oil phase. From the results, the corn oil concentration was optimized as 50 % for phantom studies. The rotational correlation time also increases with increasing concentration of corn oil. The permeable and impermeable nature of nitroxyl spin probes was demonstrated. These results will be useful...

A series of strontium oxide functionalized graphene nanoflakes were designed and their optoelectronic properties were studied for enhanced photocatalytic activity. The efficiency of designed molecules was studied using various parameters such as HOMO-LUMO energy gap, light harvesting efficiency and exciton binding energy. The computed results show that by increasing the degree of functionalization of strontium oxide leads to lowering the band gap of hydrogen terminated graphene nanoflakes. Furthermore, the study explores the role of strontium oxide functionalization in Frontier Molecular Orbitals, ionization potential, electron affinity, exciton binding energy and light harvesting efficiency of designed molecules. The infrared and Raman spectra were simulated for pure and SrO functionalized graphene nanoflakes. The electron rich and electron deficient regions which are favorable for electrophilic and nucleophilic attacks respectively were analyzed using molecular electrostatic potential surface analysis.

The molecular structure of fullerene (C60) molecule was optimized by the DFT/B3LYP method with 6-31G and 6-31G(d,p) basis sets using Gaussian 09 program. The vibrational frequencies were calculated for the optimized molecular structure of the molecule. The calculated vibrational frequencies confirm that the molecular structure of the molecule was located at the minimum energy potential energy surface. The calculated vibrational frequencies were assigned on the basis of functional group analysis and also confirmed using the GaussView 05 software. The frontier molecular orbitals analysis was carried out. The FMOs related molecular properties were predicted. The higher ionization potential, higher electron affinity, higher softness, lower band gap energy and lower hardness values were obtained, which confirm that the fullerene molecule has a higher molecular reactivity. The Mulliken atomic charge distribution of the molecule was also calculated. Hence, these results play an important role due to its potentia...

The substitution effects on the first order hyperpolarizability value of (X-methylphenyl)-5-nitro-6-amino-3-pyridinecarboxmide (X-MPNAPC),{X=2,3,4,5,6}molecule was calculated with the aid of density functional theory calculations. The optimized molecular structure of urea and (X-methylphenyl)-5-nitro-6-amino-3-pyridinecarboxmide (X-MPNAPC), {X=2,3,4,5,6} were predicted by the DFT/B3LYP method with cc-pVTZ basis set. The higher first order hyperpolarizability values were obtained for all molecules compared with the urea, which confirm that the higher nonlinear optical activity of the molecules. The frontier molecular orbitals (FMOs) analysis was carried out and their related molecular properties were calculated. The higher first order hyperpolarizability value was obtained for 4-MPNAPC molecule compared with other molecules, which indicates that the lower energy gap and extended π-conjugated bridge between the donor and acceptor group leads to the higher NLO activity of the molecule. Hence, this present in...

The Electron spin resonance studies on the reduction process of nitroxyl spin probes were carried out for 1mM 14N- labeled nitroxyl radicals in pure water and 1 mM concentration of ascorbic acid as a function of time. The electron spin resonance parameters, such as line width, hyperfine coupling constant, g-factor, signal intensity ratio and rotational correlation time were estimated. The 3-carbamoyl-PROXYL radical has narrowest line width and fast tumbling motion compared with 3-carboxy-PROXYL, 4-methoxy-TEMPO, and 4-acetamido-TEMPO radicals. 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 3-carbamoyl-PROXYL has long half life time and high stability compared with 3-carboxy-PROXYL, 4-methoxy-TEMPO and 4-acetamido-TEMPO radicals. Therefore, this study reveals that the 3-carbamoyl-PROXYL radical can act as a good redox sensitive spin probe for Overhauser-enhanced Magnetic Resonance Imaging.

An insilico and density functional theory (DFT) calculations were carried out for (X-methylphenyl)-5-nitro-6-amino-3-pyridinecarboxmide (X-MPNAPC),{X=2,3,4,5,6} to evaluate the potential inhibitors for Alzheimer’s disease. The molecular structure of 2-MPNAPC, 3-MPNAPC, 4-MPNAPC, 5-MPNAPC and 6-MPNAPC molecules was optimized by the DFT/B3LYP method with cc-pVTZ basis set using the Gaussian 09 program. The inhibitory nature of the molecules against enzyme acetylcholinesterase (AChE) catalyzes was evaluated by molecular docking studies. The molecular docking parameters such as binding energy, inhibition constant and intermolecular energy were calculated by the AutoDock 4.0 software. The higher binding energy, intermolecular energy and lower inhibition constant values suggested that the 2-MPNAPC molecule has higher inhibitory nature against the AChE catalyzes, which confirm that the 2-MPNAPC molecule is a potential inhibitor for the Alzheimer’s disease. The molecular reactivity was also studied by the frontier molecular orbitals analysis.An insilico and density functional theory (DFT) calculations were carried out for (X-methylphenyl)-5-nitro-6-amino-3-pyridinecarboxmide (X-MPNAPC),{X=2,3,4,5,6} to evaluate the potential inhibitors for Alzheimer’s disease. The molecular structure of 2-MPNAPC, 3-MPNAPC, 4-MPNAPC, 5-MPNAPC and 6-MPNAPC molecules was optimized by the DFT/B3LYP method with cc-pVTZ basis set using the Gaussian 09 program. The inhibitory nature of the molecules against enzyme acetylcholinesterase (AChE) catalyzes was evaluated by molecular docking studies. The molecular docking parameters such as binding energy, inhibition constant and intermolecular energy were calculated by the AutoDock 4.0 software. The higher binding energy, intermolecular energy and lower inhibition constant values suggested that the 2-MPNAPC molecule has higher inhibitory nature against the AChE catalyzes, which confirm that the 2-MPNAPC molecule is a potential inhibitor for the Alzheimer’s disease. The molecular reactivity was also studied by the frontie...

Polyaniline (PANI) and its composites PANI-ZnO (Zinc oxide) and PANI-ZnO-GO (Graphene oxide) were successfully constructed. These materials were characterized by electron spin resonance (ESR) technique and ultraviolet visible spectrometry. The parameters such as line width, g-factor and spin concentration were deduced from ESR spectra, from the results the radical cation stabilization of PANI, PANI-ZnO and PANI-ZnO-GO composites were compared by the polaron and bipolaron formation. The absorption features obtained in the UV absorption spectra reveal the band gap of these modified PANI composites and also predicted the information of increasing and decreasing features of signal intensity and spin concentration.

Electron spin resonance (ESR) studies were carried out for 2 mM 14N-labeled deuterated 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) and 3-carboxy-2,2,5,5,-tetramethyl-pyrrolidin-1-oxyl (carboxy-PROXYL) in pure water and various concentrations of liposomal solution by using an L-band ESR spectrometer. The ESR parameters, such as the line width, hyperfine coupling constant, g-factor, rotational correlation time and partition parameter, were reported for the samples. The changes in the line width were observed for 14N-labeled deuterated MC-PROXYL and carboxy-PROXYL in liposomal solution. The hyperfine coupling constant was observed for both nitroxyl spin probes. The permeable and impermeable nature of nitroxyl radicals was demonstrated using the ESR L-band spectra. The rotational correlation time increases with increasing concentration of liposome. The partition parameter for 14N-labeled deuterated MC-PROXYL in liposomal solution increases with increasing concentration of liposome, which reveals that the nitroxyl spin probe permeates into lipid membrane. The lipid peaks were observed for 2 mM 14N-labeled deuterated MC-PROXYL in 200, 300 and 400 mM liposomal concentration. The lipid peaks were not observed for 14N-labeled deuterated carboxy-PROXYL. These results indicate the permeable and impermeable nature of 14N-labeled deuterated nitroxyl spin probe.

The structural and magnetic properties of polyaniline (PANI)- and threonine (T)-doped polyaniline composites were characterized by using FTIR, UV-Vis, and electron paramagnetic resonance (EPR) spectroscopic techniques. The FTIR, UV-Vis, and X-band EPR spectra were recorded for PANI- and threonine-doped polyaniline (PANI-T) composites. The increased intensity of the IR bands in PANI-T composites is due to the increasing dopant concentration. The observed red shift corresponding to the N-H ··· N mode indicates the hydrogen bond formation in between the PANI and threonine molecule. The observed decrease in spectral intensity of the UV-Vis spectrum of the PANI-T composite confirms the occurrence of the protonation at the imine nitrogen sites. The EPR parameters such as line width, g factor, line asymmetry parameter, signal intensity, and spin concentration values were estimated. The EPR spectrum of PANI clearly indicates the presence of unpaired polaron. The EPR signal intensity and spin concentratio...

The mobility studies on 14N-labeled TEMPONE, TEMPO, carbamoyl-PROXYL, carboxy-PROXYL in high viscous liquid were carried out on a 300 MHz electron spin resonance (ESR) spectrometer. The ESR parameters, such as a line width, signal intensity ratio, g-factor, hyperfine coupling constant and correlation time, were determined. The line width broadening increases twofold in high viscous samples of 14N-labeled carbamoyl-PROXYL and carboxy-PROXYL, but this line broadening is negligibly small in the high viscous sample (85% glycerol) of 14N-labeled TEMPO. The correlation time also increases (~30 times) in the high viscous sample (85% glycerol) of 14N-labeled carbamoyl-PROXYL and carboxy-PROXYL, but there is no considerable increase in the high viscous sample of 14N-labeled TEMPO. TEMPONE has the narrowest line width and is also highly sensitive to viscosity. The correlation time increases (~13 times) in the high viscous sample (85% glycerol) of 14N-labeled TEMPONE. Therefore, this study reveals that the 14N-labeled TEMPONE radical is the most suitable spin probe for in vivo studies in high viscous biological fluids.

Overhauser-enhanced magnetic resonance imaging (OMRI) studies of a membrane-permeable nitroxyl spin probe, 2 H-enriched 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL), used in simultaneous molecular imaging is reported. Phantom imaging was performed with liposomal solutions of MC-PROXYL at varying spin probe and liposome concentrations using a field-cycle mode, custom-built OMRI scanner. Dynamic nuclear polarization (DNP) spectra of the liposomal solution of the spin probe, measured at 14.529 mT using a 5 mT sweep of the electron paramagnetic resonance (EPR) irradiation field showed splitting of the low and high filed hyperfine lines. Spectral measurements using D 2 O and a spin broadening agent, K 3 Fe(CN) 6 confirmed that these peaks originated from water molecules in two different environments, compartmentalized with liposomes. The nuclear Overhauser enhancement measured at different EPR irradiation times and power levels showed reduction in water nuclear magnetic resonance (NMR) signal enhancement in liposomal membrane due to the reduction in the coupling constant, ρ . This study illustrates that OMRI can be used to differentiate between the intra- and extra- membrane water by loading the liposome vesicles with a lipid-permeable nitroxyl spin probe.

Electron spin resonance (ESR) studies were carried out for permeable 2mM 14N-labeled deutrated 3 Methoxy carbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) in pure water and 1mM, 2mM, 3mM, 4mM concentration of 14N-labeled deutrated MC-PROXYL in 400mM concentration of liposomal solution by using a 300 MHz ESR spectrometer. The ESR parameters such as linewidth, hyperfine coupling constant, g-factor, partition parameter and permeability were reported for these samples. The line broadening was observed for the nitroxyl spin probe in the liposomal solution. The line broadening indicates that the high viscous nature of the liposomal solution. The partition parameter and permeability values indicate the maximum diffusion of nitroxyl spin probes in the bilayer lipid membranes at 2 mM concentration of nitroxyl radical. This study illustrates that ESR can be used to differentiate between the intra and extra- membrane water by loading the liposome vesicles with a lipid-permeable nitroxyl spin probe. From th...

Infrared and laser Raman spectral investigations of [Ni(II)(dppe)Cl2] and [Co(III)(dppe)2Cl2]PF6 have been made to determine the conformation and nature of bonding in Ni(II) and Co(III) dppe complexes. The stereochemistry of the two forms of these complexes has been confirmed. The role of steric interferences in cis-Planar [Ni(II)(dppe)Cl2] complex is interpreted in terms of reduction in symmetry upon coordination. The strong trans influence of the chelating dppe ligand is observed in the [Co(III)(dppe)2Cl2]PF6 complex. Both complexes exhibit the effect of crystalline field on molecular vibrations. The Fermi resonance overtone is also observed in these complexes.

Electron spin resonance (ESR) studies were carried out for 2mM 14N labeled deutrated permeable 3- methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) in pure water, 1 mM, 2 mM, 3 mM and 4 mM concentration of MC-PROXYL in 300 mM concentration of liposomal solution by using a L-band ESR spectrometer. The ESR parameters such as linewidth, hyperfine coupling constant, g-factor, partition parameter and permeability were reported. The partition parameter and permeability values indicate the maximum spin distribution in the lipid phase at 2 mM concentration. This study illustrates that ESR can be used to differentiate between the intra and extra-membrane water by loading the liposome vesicles with a lipid-permeable nitroxyl spin probe. From the ESR results, the radical concentration was optimized as 2 mM in liposomal solution for ESR phantom studies and experiments.

The Electron spin resonance studies on the reduction process of nitroxyl spin probes were carried out for 1mM 14N labeled nitroxyl radicals in pure water and 1 mM concentration of ascorbic acid as a function of time. The electron spin resonance parameters such as signal intensity ratio, line width, g-value, hyperfine coupling constant and rotational correlation time were determined. The half life time was estimated for 1mM 14N labeled nitroxyl radicals in 1 mM concentration of ascorbic acid. The ESR study reveals that the TEMPONE has narrowest line width and fast tumbling motion compared with TEMPO and TEMPOL. From the results, TEMPONE has long half life time and high stability compared with TEMPO and TEMPOL radical. Therefore, this study reveals that the TEMPONE radical can act as a good redox sensitive spin probe for molecular imaging.

Electron spin resonance (ESR) studies were carried out for 2mM 14N-labeled deutrated 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) and 3-carboxy-2,2,5,5,-tetramethyl-1-pyrrolidinyloxy (carboxy-PROXYL) in pure water and various concentrations of liposomal solutions by using 300 MHz ESR spectrometer. The ESR parameters such as the line width, hyperfine coupling constant, g-factor, rotational correlation time, partition parameter and permeability were reported for the samples. The permeable and impermeable nature of nitroxyl spin probes was demonstrated. The increased rotational correlation time was observed for MC-PROXYL, which indicates the permeable and less mobile nature of the nitroxyl spin probe. The obtained partition parameter and permeability values are used to quantify the permeable nature of the nitroxyl spin probe. The peaks correspond to lipid phase were observed for MC-PROXYL in liposomal solution, but that peak was not observed for carboxy-PROXYL. These results indicate ...

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.

Electron spin resonance studies were carried out for 2mM 14N labeled 2H enriched 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) in pure water and 100, 200, 300, 400 mM concentrations of liposomal solution and 3–carboxy-2,2,5,5,-tetramethyl-1-pyrrolidinyloxy (carboxy-PROXYL) in pure water and 400 mM concentration of liposomal solution by using L-band ESR spectrometer. This study reveals that the permeability of MC-PROXYL in liposomal solution and impermeability of carboxy-PROXYL in 400 mM concentration of liposomal solution. This study illustrates that the ESR can be used to differentiate between the intra-and extra-membrane water by loading the liposome vesicles with a lipid permeable nitroxyl spin probe. The lipid membrane permeability of two different nitroxyl spin probes was demonstrated.

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.

DNP parameters relevant to Overhauser-enhanced magnetic resonance imaging (OMRI) are reported for a few nitroxyl radicals and their corresponding (15)N and (2)H enriched analogues, used in simultaneous imaging by OMRI. DNP enhancement was measured at 14.529 mT, using a custom-built scanner operating in a field-cycled mode, for different concentrations, ESR irradiation times and RF power levels. DNP enhancements increased with agent concentration up to 2.5 mM and decreased above 3 mM, in tune with ESR line broadening measured at X-band as a function of the agent concentration. The proton spin-lattice relaxation times (T(1)) measured at very low Zeeman field (14.529 mT) and the longitudinal relaxivity parameters were estimated. The relaxivity parameters were in good agreement with those independently computed from the linear region of the concentration dependent enhancement. The leakage factor showed an asymptotic increase with increasing agent concentration. The coupling parameters of (14)N- and (15)N-labeled carbamoyl-PROXYL showed the interaction between the electron and nuclear spins to be mainly dipolar in origin. Upon (2)H labeling, about 70% and 40% increases in enhancement for (15)N- and (14)N-labeled nitroxyl agents were observed, respectively. It is envisaged that the results reported here may enable better understanding of the factors determining DNP enhancement to design suitable 'beacons' for simultaneous molecular imaging by OMRI.