Search

Tioconazole (TCZ), an antifungal medication of the imidazole class has been investigated by experimental FT-IR, FT-Raman, UV–vis and NMR spectroscopy. The optimized molecular geometry and vibrational wave numbers were calculated by DFT/B3LYP/6–311++G(d, p). The detailed vibrational assignments were made by Potential Energy Distribution. The electrophilic and nucleophilic reactive sites were studied using MEP surface. The NBO analysis has been done to describe various hyper-conjugative interactions responsible for the stabilization of the molecule. The 1H NMR chemical shifts were calculated by GIAO method and these matched well with the experimental results, indicating the accuracy of calculation method. TD-DFT calculations have been performed to determine several electronic properties like excitation energies, oscillator strengths, wavelengths and HOMO-LUMO energies. The lipophilicity and aqueous solubility of the compound have been predicted by ALOGPS method. The log P value for TCZ approaches that this compound is less recommended for oral administration. Docking studies have been made to predict the binding orientation, affinity and antifungal activity of the compound. [ABSTRACT FROM AUTHOR]

Glycosylphosphatidylinositols (GPIs) anchored proteins are commonly localized onto lipid rafts. These extracellular proteins participate in a variety of cellular functions, including as receptors for viruses and toxins. Intracellular trafficking of World Health Organization recognized mosquito-larvicidal BinAB toxin is mediated via GPI-anchored Cqm1 receptor protein in Culex mosquitoes. We confirmed conformational change in Cqm1 dimer on interaction with BinA/BinB proteins by dynamic light scattering, modelling of hydrodynamic parameters using the atomic structures, and synchrotron Small Angle solution X-ray scattering (SAXS). A reliable model of the receptor-BinB complex was also constructed from joint SAXS/SANS refinement. We confirmed electrostatic interactions of the Cqm1 ectodomain with lipid rafts reconstituted in model membranes and report receptor-dependent impairment of model liposomes by BinA/B proteins. Liposomal disruption was toxin concentration-dependent as monitored by the release of encapsulated carboxyfluorescein dye. Interestingly, BinA alone, without BinB, showed efficient efflux of the fluorescent dye in agreement with the reported high larvicidal activity of BinA variants. The study provides insight into BinA/B toxin internalization mechanism in the membrane model that is toxin internalization is mediated via receptor-dependent pore formation mechanism. It also suggests a tangible and environmentally safe strategy for control of mosquito population. [ABSTRACT FROM AUTHOR]

We theoretically investigate the conformational properties of semiflexible dendrimers where the semiflexibility is implemented by topologically restricting the bond directions and orientations of the respective bond vectors. Molecular size (radius of gyration, Rg and Wiener index, W), shape factor ρ, configurational free energy F, and the static structure factor, S(q) of semiflexible dendrimers are analyzed as a function of the bond orientation angle, [lowercase_phi_synonym]. The size of the lower generation dendrimers decreases with increasing [lowercase_phi_synonym] throughout the entire range of [lowercase_phi_synonym], [lowercase_phi_synonym] ∈ (0, π). The higher generation dendrimers show a non-uniform behavior, for compressed conformations the size decreases with increasing [lowercase_phi_synonym], while for the expanded ones it increases with the increase in [lowercase_phi_synonym]. A conformational transition occurs for the higher generation dendrimers from the limiting value of the hard sphere to an ideal chain with the change in [lowercase_phi_synonym]. This conformational transition at [lowercase_phi_synonym] = π/2 is also reflected in the configurational free energy. The configurational free energy exhibits a discontinuous behavior with the variation of [lowercase_phi_synonym], and this discontinuity occurs at [lowercase_phi_synonym] = π/2. However, no such conformational transition is observed with the variation of the bond direction angle, θ, generation, G and functionality, f of the semiflexible dendrimers. The flexible dendrimer, i.e., at [lowercase_phi_synonym] = π/2 is flanked between the compressed and expanded conformations of the semiflexible dendrimers resembling a hard sphere. The Kratky plot of the structure factor of all conformations quantitatively match with the results obtained from experiments and simulations in the low q-region in respect to the position of the major Kratky peak. For higher wave numbers, the Kratky plots for all conformations of semiflexible dendrimers agree with earlier theoretical results of model dendrimers [R. La Ferla, J. Chem. Phys. 106, 688 (1997); F. Ganazzoli, R. La Ferla, and G. Raffaini, Macromolecules 34, 4222 (2001)] but are in sharp contrast to the experimental [S. Rathgeber et al., J. Chem. Phys. 117, 4047 (2002); S. Rathgeber, T. Pakula, and V. Urban, J. Chem. Phys. 121, 3840 (2004)] and simulated [M. L. Mansfield and L. I. Klushin, Macromolecules 26, 4262 (1993)] scattering curves for the higher generation dendrimers. All compressed conformations (0 < [lowercase_phi_synonym] < π/2) behave as compact hard spheres, while the expanded conformations (π/2 < [lowercase_phi_synonym] < π) are relatively more open, partially decongesting the steric crowding among the monomers with increasing [lowercase_phi_synonym]. [ABSTRACT FROM AUTHOR]

Introduction: Papaya (Carica papaya Linn.) belongs to the family Caricaceae and is well known for its therapeutic and nutritional properties all over the world. The different parts of the papaya plant have been used since ancient times for its therapeutic applications. Herein, we aimed to review the anticancer, anti-inflammatory, antidiabetic and antiviral activities of papaya leaf. Methods: All information presented in this review article regarding the therapeutic application of Carica papaya leaf extract has been acquired by approaching various electronic databases, including Scopus, Google scholar, Web of science, and PubMed. The keywords Carica papaya, anticancer, anti-inflammatory, immunomodulatory, and phytochemicals were explored until December 2019. Results: The papaya plant, including fruit, leaf, seed, bark, latex, and their ingredients play a major role in the management of disease progression. Carica papaya leaf contains active components such as alkaloids, glycosides, tannins, saponins, and flavonoids, which are responsible for its medicinal activity. Additionally, the leaf juice of papaya increases the platelet counts in people suffering from dengue fever. Conclusion: The major findings revealed that papaya leaf extract has strong medicinal properties such as antibacterial, antiviral, antitumor, hypoglycaemic and anti-inflammatory activity. Furthermore, clinical trials are needed to explore the medicative potential of papaya leaf. [ABSTRACT FROM AUTHOR]

A collective experimental and theoretical study was conducted on the molecular structure and vibrational spectra of nonlinear optical chalcone derivative (2E)-3-[4-(methylsulfanyl) phenyl]-1-(3-bromophenyl) prop-2-en-1-one (3Br4MSP). The FT-IR and FT-Raman spectra of the molecule in the solid phase have been recorded. Density functional theory (DFT) calculations at B3LYP level with 6–311++G (d,p) basis set have been carried out to derive useful information about the molecular structure and to assign the relevant electronic and vibrational features. These calculations reveal that the optimized geometry closely resembles the experimental XRD data. The vibrational spectra were analyzed on the basis of the potential energy distribution (PED) of each vibrational mode, which allowed us to obtain a quantitative as well as qualitative interpretation of FT-IR and FT-Raman spectra. The UV–vis spectrum was recorded in methanol solution. The excited state properties have been determined by TD-DFT method and the effect of solvent was analyzed by PCM model. The most prominent transition corresponds to π→π ∗ . The reactivity parameters as chemical potential, global hardness, and electrophilicity index have also been calculated. To provide an explicit assignment and analysis of 13 C and 1 H NMR spectra, theoretical calculations on chemical shift of the title compound were done through GIAO method at B3LYP/6-311++G (d,p) level. The Mulliken's population analysis shows one of the simplest pictures of charge distribution. The standard statistical thermodynamic functions like heat capacity at constant pressure (C o p,m ), entropy (S o m ) and enthalpy (H o m ) were obtained from the theoretical harmonic frequencies for the optimized molecule. The nonlinear optical properties of title molecule are also addressed theoretically. Two contributions, vibrational and electronic, to the electrical properties polarizability and first order hyperpolarizability of 3Br4MSP have been evaluated using the self-consistent field wave functions within the double harmonic oscillator approximation. [ABSTRACT FROM AUTHOR]

In the present work, a combined experimental and theoretical study on ground state molecular structure, spectroscopic and nonlinear optical properties of the chalcone derivative 3-(2-Chloro-6-fluorophenyl)-1-(2-thienyl) prop-2-en-1-one (2C6F2SC) is reported. Initial geometry generated from single crystal X-ray diffraction parameters was minimized at DFT level employing B3LYP/6-311++G (d,p) without any constraint to the potential energy surface. The molecule has been characterized using various experimental techniques FT-IR, FT-Raman, UV–Vis, 1 H NMR, TD-THz and the spectroscopic data have been analyzed theoretically by Density Functional Theory (DFT) method. Harmonic vibrational frequencies were calculated theoretically using the optimized ground state geometry and the spectra were interpreted by means of potential energy distribution. Time Dependent Density Functional Theory (TD-DFT) has been used to calculate energies, absorption wavelengths, oscillator strengths of electronic singlet–singlet transitions. The calculated energy and oscillator strength complement with the experimental findings. The HOMO–LUMO energy gap explains the charge interaction taking place within the molecule. Good correlations between the experimental 1 H NMR chemical shifts and calculated GIAO shielding tensors were found. Stability of the molecule, hyperconjugative interactions and charge delocalization has been analyzed by natural bond orbital (NBO) analysis. The first order hyperpolarizability (β) of this molecular system and related properties (μ, <α> and Δα) have been calculated using the finite-field approach. [ABSTRACT FROM AUTHOR]

• Synthesis of a focused library of novel triazolylpyrrolobenzodaizepinone derivatives. • Compound (4l) showed extraordinary in vitro COX–2 inhibition (IC 50 = 18.9 nM)]. • It also showed the best selectivity (COX–1/COX–2 = 1060). • It acted as effective in vivo anti–inflammatory activity without inducing gastric ulceration. • Was found safe in cell toxicity studies on hela cells. • Compound (4l) could act as a potential lead candidate. COX–2, a key enzyme that catalyzes the rate–limiting steps in the conversion of arachidonic acid to prostaglandins, plays a pivotal role in the inflammatory process. Therapeutic utilization of selective COX–2 inhibitors has been considered an effective approach for treating inflammation with emasculated side effects. This study describes the design and enantioselective synthesis of a library of twenty–six novel 1,2,3–triazolylpyrrolobenzodiazepinone derivatives. The molecules were found to exhibit good drug–like properties as implied by the ADMET studies. Nine compounds of the library showing promising results in silico studies were evaluated for cell toxicity on HeLa cells and in vitro COX–1/COX–2 enzyme inhibition. Compounds (2b) and (4l) were found to significantly inhibit COX–2 in vitro in comparison to the standard and compound (4l) with S–geometry showed extraordinary COX–2 inhibition (IC 50 = 18.9 nM) and the best selectivity (COX–1/COX–2 = 1060). (4l) also exhibited the most potent anti–inflammatory activity in vivo in comparison to the standard drugs (Indomethacin and Celecoxib) without inducing any gastric ulceration. Molecular modeling studies aided in the understanding of the interaction modes between this compound and the COX–2 enzyme. Findings in this study may thus serve as a pivotal avenue for developing next–generation selective COX–2 anti–inflammatory drugs using pyrrolobenzodiazepinone (PBD), scaffold. [Display omitted] [ABSTRACT FROM AUTHOR]

In the present investigation, ultra low carbon steel samples were deformed in plane strain compression mode in a deformation simulator. The deformation was carried out at four different temperatures in the warm rolling region (293, 473, 673 and 873 K) upto 70% strain at two different strain rates (0.1/s and 1/s). Subsequently, all the deformed samples were fully recrystallized at 1073 K. Afterwards, all the deformed and fully recrystallized samples were subjected to detailed microstructural characterization using optical microscope, scanning electron microscope and electron backscattered diffraction. Bulk texture was measured for all the samples by X-ray diffraction. In-grain misorientation developments (kernel average misorientations) were estimated for the deformed γ-fibre (ND//<111>) and α-fibre (RD//<110>). Deformed γ-fibre showed an increase in in-grain misorientation at intermediate deformation temperatures. This increase was explained by using the plastic instability criterion. After complete recrystallization, the γ-fibre strengthened for deformation at lower temperatures (293 K and 473 K), while Goss texture developed for samples deformed at higher temperatures (673 K and 873 K). [ABSTRACT FROM AUTHOR]

In the present work the structural and spectral characteristics of 5-benzyl-2-thiohydantoin (5-BTH) have been studied by methods of infrared, Raman spectroscopy and quantum chemistry. Electrostatic potential surface, optimized geometry, harmonic vibrational frequencies, infrared intensities and activities of Raman scattering were calculated by density functional theory (DFT) employing B3LYP with complete relaxation in the potential energy surface using 6-311G++(d,p) basis set. Our results support the hydrogen bonding pattern proposed by reported crystalline structure. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital (NBO) analysis. The 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. UV-vis spectrum of the compound was recorded in methanol solvent. The TD-DFT calculations have been performed to explore the influence of electronic absorption spectra in the gas phase, as well as in solution environment using PCM and 6-311++G(d,p) basis set. In addition, the thermodynamic properties of the compound were calculated at different temperatures and corresponding relations between the properties and temperature were also studied. [ABSTRACT FROM AUTHOR]

Highlights: [•] FT-IR spectrum of synthesized compound recorded and compared with the theoretical results. [•] By using TD-DFT/6-31G method, electronic transitions for title compound are predicted. [•] The 1HNMR spectrum has also been studied. [•] The electronic descriptors have been used to explain chemical reactivity. [Copyright &y& Elsevier]

Highlights: [•] FT-IR spectrum of the studied compound was recorded and compared with the theoretical result. [•] To determine the hyperconjugative interactions NBO analysis was performed. [•] Theoretical calculated (β 0) indicates the NLO response of the investigated molecule. [Copyright &y& Elsevier]

Highlights: [•] FT-IR spectrum of the studied compound has been compared with the theoretical results. [•] The resonance assisted intramolecular hydrogen bonds has been characterized using AIM calculations.. [•] The electronic transitions for the synthesized compound have been predicted. [•] The 1H NMR spectrum for title compound has been studied.. [•] Chemical reactivity has been explained with the aid of electronic descriptors. [Copyright &y& Elsevier]

Highlights: [•] FT-IR spectrum of the studied compound was recorded and compared with the theoretical result. [•] All the theoretical calculations were made using DFT/B3LYP/6-31G(d,p) method. [•] NBO analysis are performed to determine the hyperconjugative interactions. [•] QTAIM analysis are performed to determine hydrogen bonding. [•] Chemical reactivity has been explained with the aid of electronic descriptors. [Copyright &y& Elsevier]

Highlights: [•] FT-IR spectrum of the title compound was recorded and compared with the theoretical results. [•] The theoretical calculations were made using DFT/B3LYP/6-31G(d,p) method. [•] By using TD-DFT/6-31G method, electronic spectra for title compound have been predicted. [•] Chemical reactivity has been explained with the aid of global and local electronic descriptors. [•] The computed value of first hyperpolarizability have been also predicted. [ABSTRACT FROM AUTHOR]

Abstract: A detailed spectroscopic analyses of a newly synthesized ethyl 2-cyano-3-[5-(hydrazinooxalyl–hydrazonomethyl)-1H-pyrrol-2-yl]-acrylate (3) have been carried out using 1H and 13C NMR, UV–Visible, FT-IR and mass spectroscopic techniques. All the quantum chemical calculations have been carried out using DFT level of theory, B3LYP functional and 6-31G(d,p) as basis set. The 1H and 13C NMR chemical shifts are calculated using gauge including atomic orbitals (GIAOs) approach in DMSO-d 6. TD-DFT is used to calculate the energy (E), oscillatory strength (f) and wavelength absorption maxima (λ max) of various electronic transitions and their nature within molecule. Natural bond orbital (NBO) analysis is carried out to investigate the various intra and intermolecular interactions in dimer and their corresponding second order stabilization energy (E (2)). A combined theoretical and experimental vibrational analysis confirms the existence of dimer and the binding energy of dimer is calculated as 9.21kcal/mol using DFT calculations. To determine the energy and nature of different interactions topological parameters at bond critical points (BCPs) have been analyzed by Bader’s ‘atoms in molecules’ (AIMs) theory in detail. Electrophilic charge transfer (ECT) is calculated to investigate the relative electrophilic or nucleophilic behavior of reactant molecules involved in chemical reaction. Global electrophilicity index (ω =5.5836eV) shows that title molecule (3) is a strong electrophile. The local reactivity descriptors such as Fukui functions , local softness and electrophilicity indices analyses are performed to determine the reactive sites within molecule. [Copyright &y& Elsevier]

Ethyl-4-[(2,4-dinitrophenyl)-hydrazonomethyl]-3,5-dimethyl-1 H-pyrrole-2-carboxylate ( 3) has been newly synthesized by the condensation of ethyl-4-formyl-3,5-dimethyl-1 H-pyrrole-2-carboxylate and 2,4-dinitrophenylhydrazine, characterized by FT-IR, H NMR, UV-Vis, DART Mass and elemental analysis. The formation of compound ( 3) and its properties have been evaluated by quantum chemical calculations. The calculated thermodynamic parameters show that the formation reaction of ( 3) is exothermic and spontaneous at room temperature. The vibrational analysis indicates that ( 3) forms dimer in the solid state by heteronuclear double hydrogen bonding (N-H···O). Topological parameters electron density ( ρ), Laplacian of electron density (∇ ρ), and total electron energy density ( H) at bond critical points (BCP) have been analyzed using 'atoms in molecules' (AIM) theory. The interaction energies of dimer formation using DFT and AIM calculations are found to be −14.6509 and −15.5308 kcal/mol, respectively. AIM ellipticity analysis confirms the presence of resonance-assisted hydrogen bonding in dimer. The global electrophilicity index (ω = 5.91 eV) shows that title molecule is a strong electrophile. The local reactivity descriptors Fukui functions ( f, f), softness ( s, s), and electrophilicity indices ( ω, ω) analyses are performed to determine the reactive sites within molecule. [ABSTRACT FROM AUTHOR]

Abstract: In the present paper, a new ethyl 4-[2-(carbamoyl)hydrazinylidene]-3,5-dimethyl-1H-pyrrole-2-carboxylate (3) has been synthesized and characterized by 1H NMR, UV–Visible, FT-IR and Mass spectroscopy. The formation of the compound and its properties have also been evaluated by quantum chemical calculations using density functional theory (DFT), B3LYP functional and 6-31G(d,p) as basis set. The calculated thermodynamic parameters show that the formation of (3) is an exothermic and spontaneous reaction at room temperature. 1H NMR chemical shifts are calculated using gauge including atomic orbitals (GIAO) approach in DMSO-d 6 as solvent. Time dependent density functional theory (TD-DFT) is used to calculate the energy (E), oscillator strength (f) and wavelength absorption maxima (λ max) of various electronic transitions and their nature within the molecule. NBO analysis is carried out to investigate the stabilization energy of various intra and intermolecular interactions in molecular system. The vibrational analysis indicates the formation of dimer in the solid state by intermolecular heteronuclear hydrogen bonding (NO) and the binding energy of dimer is calculated to be 10.40kcal/mol, using DFT calculations. Topological parameters at bond critical points (BCP) are calculated to analyze the strength and nature of various types of intra and intermolecular interactions in dimer by Bader’s ‘Atoms in molecules’ AIM theory in detail. The local reactivity descriptors such as Fukui functions (), local softnesses () and electrophilicity indices () analyses are performed to determine the reactive sites within molecule. [Copyright &y& Elsevier]

Abstract: In the present work, a detailed spectroscopic analysis of 4-(benzyloxy)benzaldehyde thiosemicarbazone (3) has been carried out using 1H NMR, 13C NMR, UV–Visible and FT-IR spectroscopic techniques. The quantum chemical calculations have been carried out using DFT level of theory, B3LYP functional and 6-31G(d,p) basis set. The calculated thermodynamic parameters show that the formation of 3 is an exothermic and spontaneous reaction at 25°C. The vibrational analysis indicates the formation of dimer in the solid state by intermolecular hydrogen bonding (NSe binding energy of dimer is calculated to be 11.2kcal/mol, using DFT calculation. NBO analysis is carried out to investigate the charge transfer in various intra and intermolecular interactions involved in dimer. Topological parameters at bond critical points (BCPs) are calculated to analyze the strength and nature of various intra and intermolecular interactions in dimer by Bader’s ‘Atoms in molecules’ AIM theory in detail. The local reactivity descriptors such as Fukui functions , local softnesses and electrophilicity indices analysis are performed to determine the reactive sites within molecule. Non linear optical (NLO) behavior of title compound is investigated by the computed value of first hyperpolarizability (β 0). [Copyright &y& Elsevier]

Abstract: A new ethyl-4-{[(2,4-dinitrophenyl)-hydrazono]-ethyl}-3,5-dimethyl-1H-pyrrole-2-carboxylate (EDPHEDPC) has been synthesized and characterized by FT-IR, 1H NMR, UV–vis, DART-Mass spectroscopy and elemental analysis. Quantum chemical calculations have been performed by DFT level of theory using B3LYP functional and 6-31G(d,p) as basis set. The 1H NMR chemical shifts are calculated using gauge including atomic orbitals (GIAO) approach in DMSO as solvent. The time dependent density functional theory (TD-DFT) is used to find the various electronic transitions and their nature within molecule. A combined theoretical and experimental wavenumber analysis confirms the existence of dimer. Topological parameters such as electron density (ρ BCP), Laplacian of electron density (▿2 ρ BCP), kinetic electron energy density (G BCP), potential electron density (V BCP) and the total electron energy density (H BCP) at bond critical points (BCP) have been analyzed by Bader''s ‘Atoms in molecules’ AIM theory in detail. The intermolecular hydrogen bond energy of dimer is calculated as −12.51kcal/mol using AIM calculations. AIM ellipticity analysis is carried out to confirm the presence of resonance assisted intra and intermolecular hydrogen bonds in dimer. The calculated thermodynamic parameters show that reaction is exothermic and non-spontaneous at room temperature. The local reactivity descriptors such as Fukui functions (f k +, f k −), local softnesses (s k −, s k +) and electrophilicity indices (ω k +, ω k −) analyses are performed to determine the reactive sites within molecule. Nonlinear optical (NLO) behavior of title compound is investigated by the computed value of first hyperpolarizability (β 0). [Copyright &y& Elsevier]

Abstract: A new ethyl 4-formyl-3,5-dimethyl-1H-pyrrole-2-carboxylate thiosemicarbazone (EFDMPCT) has been synthesized and characterized by elemental analysis and FT-IR, 1H NMR, UV–Visible, DART-mass spectroscopy. Quantum chemical calculations have been performed by DFT level of theory using B3LYP functional and 6-31G (d,p) as basis set. The calculated 1H NMR chemical shifts using gauge including atomic orbitals (GIAO) approach are in good agreement with the observed chemical shifts. The electronic transitions within molecule have been interpreted using the time dependent density functional theory (TD-DFT). The calculated and experimental wavenumbers analyses confirm the existence of dimer. Topological parameters electron density, Laplacian of electron density, kinetic electron energy density, potential electron density and the total electron energy density at the bond critical points (BCP) analyzed using ‘Atoms in Molecules’ AIM theory reveals intra and inter molecular hydrogen bonding other weaker interactions in detail. The calculated intermolecular hydrogen bond energy of dimer is −12.2176kcal/mol using AIM calculation. The results of AIM ellipticity confirm the existence of resonance assisted hydrogen bonds in dimer. The calculated thermodynamic parameters show that reaction is exothermic and non-spontaneous at room temperature. The local reactivity descriptors find the reactive sites within molecules have been calculated. [Copyright &y& Elsevier]

Abstract: In this paper we report the structural, magnetic, magnetocapacitance and dielectric properties of BiFe1−x Ni x O3 nanoceramics (with x=0, 0.1) prepared by the sol-gel method. XRD analysis showed formation of single phase nanoceramics (particle size ∼50nm by TEM). Samples of BiFe1−x Ni x O3 were divided into two parts—one of them quenched in liquid nitrogen and another sintered in the normal way. We observed the enhancement in magnetic and dielectric properties of quenched sample. The splitting of zero field cool (ZFC) and field cool (FC) magnetization curves at low temperature reveals spin- glass behavior. Quenched sample showed the enhancement of blocking temperature. [Copyright &y& Elsevier]

Abstract: The transition 111 −110 at 4.829GHz of formaldehyde (H2CO) was the first one showing the anomalous absorption, i.e., the absorption against the cosmic microwave background. Anomalous absorption is an unusual phenomena. Structure of H2CC is very similar to that of H2CO and H2CS. Both H2CO and H2CS have already been identified in a number of cosmic objects. Though H2CC is not yet identified in the cosmic objects, we propose that H2CC may be identified in cool cosmic objects through its transition 111 −110 at 4.85GHz in anomalous absorption. [ABSTRACT FROM AUTHOR]

Abstract: Spinel-perovskite nanocomposites of xCrFe2O4–(1−x)BiFeO3 with x=0.0, 0.1, 0.2, 0.3, 0.4 were prepared by sol gel method. The XRD showed the phase formation of nanocomposites at 700°C. Particle size was observed to be ∼100nm by TEM. The variation of dielectric constant and dielectric loss with frequency showed dispersion in the low frequency range. Magnetization was found to increase with increasing concentration of ferrite content. Dielectric analysis showed the conducting behaviour at higher temperature. Magnetocapacitance was also observed in the prepared nanocomposites which may be the sign of magnetoelectric coupling in the synthesized nanocomposites at room temperature. [Copyright &y& Elsevier]

Describes an approach for measuring dielectric dispersions in the microwave regime of larger aqueous-based molecules such as proteins and nucleic acids. Identification of molecular structures, changes in structures and intermolecular interactions using the method; Measurement of physiologic environments; Sensitivity of the method.

Highlights: [•] The electronic descriptors have been used to explain chemical reactivity. [•] The experimental photoluminescence spectrum has been studied. [•] The 1H NMR spectrum has been studied. [•] Theoretical and experimental FT-IR spectra results have been compared. [ABSTRACT FROM AUTHOR]

Abstract: We report the study of structural, optical and magnetic properties of (1−x)ZnO–xMgO (x=0.35, 0.40, 0.45 and 0.50) composites prepared by solid state reaction method. X-ray diffraction pattern confirms the presence of both the phases associated with ZnO (hexagonal) and MgO (cubic), which is revealed through the existence of (111) and (200) peaks in addition to ZnO peaks. The lattice parameter c as calculated using X-ray analysis undergoes shrinkage with increasing content of MgO. Microstructural analysis suggests that there is no variation in spherical elongated shape of grains with increasing concentration of MgO, where the average grain size is found to be ∼600nm. The band gap as calculated from optical absorption spectra obtained by diffuse reflectance method recorded at room temperature is tuned from 3.16 to 3.55eV. Photoluminescence spectra consist of near band edge UV emission (389nm) and defect level emission (503nm). The increase of MgO concentration leads to blue shift of UV emission peaks. The magnetic measurements conducted using SQUID at 5K temperature reveals ferromagnetism along with paramagnetic and superparamagnetic components. Saturation magnetisation (M s ) is observed to be enhanced with MgO doping. [Copyright &y& Elsevier]

Abstract: A new hydrazone, ethyl 4-[(3,5-dinitrobenzoyl)-hydrazonomethyl]-3,5-dimethyl-1H-pyrrole-2-carboxylate (PDNBAH) has been synthesized and characterized by FT-IR, 1H NMR, UV–visible spectroscopy. All the quantum chemical calculations have been performed by density functional theory (DFT), using B3LYP functional and 6-31G(d,p) as basis set. The calculated and experimental wavenumber analyses confirm the existence of dimer of PDNBAH. The calculated binding energies of dimer using DFT and Bader''s atoms in molecules (AIM) theory are −14.32 and −15.41kcal/mol respectively. The intermolecular hydrogen bond energy of dimer due to the involvement of intermolecular hetero-nuclear double hydrogen bonds (NOh pyrrolic Ne:glyph name="dbnd" />O of ester is also calculated to be equal to −12.29kcal/mol using AIM calculation. The strength and the nature of hydrogen bonding and weak interactions in dimer have been analyzed by AIM theory in detail. The presence of resonance assisted hydrogen bonds (RAHB) has been confirmed by calculated ellipticity parameters using AIM calculation. The calculated thermodynamic parameters show that the reaction is non spontaneous at room temperature. The local reactivity descriptors show that C(13) is most reactive site for nucleophilic attack. [Copyright &y& Elsevier]

Summary The small, highly conserved Kti11 alias Dph3 protein encoded by the Kluyveromyces lactis k iller t oxin i nsensitive gene KTI11/DPH3 is involved in the diphthamide modification of eukaryotic elongation factor 2 and, together with Kti13, in Elongator-dependent tRNA wobble base modifications, thereby affecting the speed and accuracy of protein biosynthesis through two distinct mechanisms. We have solved the crystal structures of Saccharomyces cerevisiae Kti13 and the Kti11/Kti13 heterodimer at 2.4 and 2.9 Å resolution, respectively, and validated interacting residues through mutational analysis in vitro and in vivo. We show that metal coordination by Kti11 and its heterodimerization with Kti13 are essential for both translational control mechanisms. Our structural and functional analyses identify Kti13 as an additional component of the diphthamide modification pathway and provide insight into the molecular mechanisms that allow the Kti11/Kti13 heterodimer to coregulate two consecutive steps in ribosomal protein synthesis. [ABSTRACT FROM AUTHOR]

• Non-linear optical (NLO) properties of a chalcone-derivative is investigated. • Structure-property relationships of the compound were analyzed. • The sites prone to electrophilic/nucleophilic sites were identified. • The lone pair and anti-bonding orbitals responsible for charge delocalization have been analyzed. • Vibrational contribution to NLO activity was explained in detail. Chalcone derivatives are known for their characteristic non-linear optical efficiency. In the present work, the relation between the molecular structure and non-linear optical properties of a synthesized chalcone derivative 4-[(1 E)-3-(5-chlorothiophen-2-yl)-3-oxoprop-1-en-1-yl] phenyl4-methylbenzene-1-sulfonate (4TPMS) have been investigated by combined experimental and theoretical approaches. The title compound 4TPMS was characterized by spectroscopic techniques viz. Raman, FT-IR, UV-vis, and 1H NMR. Further, the experimental findings were validated by quantum chemical computations. The crystalline geometry of 4TPMS was optimized to energy minima by employing density functional theory (DFT) with B3LYP/6-311++G(d,p) approximation level. Harmonic vibrational frequencies were calculated and the spectral assignments have been done by potential energy distribution (PED) analysis. Significant non-linear optical (NLO) responses of chalcone are mainly caused by charge delocalization between lone pair and antibonding molecular orbitals within the molecule. Hence, natural bond orbital (NBO) was performed to analyze the charge delocalization along with the stability of the molecule. The population analysis based on Charges from Electrostatic Potentials using a Grid based method (CHELPG) was employed to understand the electrophilic/nucleophilic reaction sites. Moreover, the time-dependent density functional theory (TD-DFT) was employed to predict the energies, absorption wavelengths (λ max) and oscillator strengths (f) of the electronic transitions. The TD-DFT calculation successfully reproduces the experimental UV-Vis spectrum of 4TPMS. The chemical shifts observed in 1H-NMR and the calculated GIAO shielding tensors also showed good agreement. A vibrational contribution to the NLO activity and the effect of charge delocalization on the NLO response were illustrated by comparing the similar kind of chalcone derivatives. [ABSTRACT FROM AUTHOR]

Abstract: A newly synthesized chalcone, Ethyl 4-[3-(2-chloro-phenyl)-acryloyl]-3,5-dimethyl-1H-pyrrole-2-carboxylate (ECPADMPC) has been characterized by 1H NMR, 13C NMR, UV–Vis, FT-IR, Mass spectroscopy and elemental analysis. Quantum chemical calculations have been performed by DFT level of theory using B3LYP functional and 6-31G(d,p) as basis set. The time dependent density functional theory (TD-DFT) is used to find the various electronic transitions within molecule. A combined theoretical and experimental wavenumber analysis confirms the existence of dimer. Topological parameters-electron density (ρ BCP), Laplacian of electron density (▿2 ρ BCP), energetic parameters-kinetic electron energy density (G BCP), potential electron density (V BCP) and the total electron energy density (H BCP) at the bond critical points (BCP) have been analyzed by ‘Atoms in molecules’ AIM theory in detail. The intermolecular hydrogen bond energy of dimer is calculated as −12.3kcal/mol using AIM calculations. AIM ellipticity analysis is carried out to confirm the presence of resonance assisted intermolecular hydrogen bonds in stabilization of dimer. The analysis clearly depicts the presence of different kind of interactions in dimer. This dimer may work as model system to understand the H-bonding interaction in biomolecules. The local reactivity descriptor analysis is performed to find the reactive sites within molecule. [Copyright &y& Elsevier]