Determination of excitation function for alpha induced reactions on 237Np and 238Pu.

The excitation function of the alpha particle-induced reactions on 237Np and 238Pu has been determined for the incident alpha energies ranging from threshold to 50 MeV using TALYS1.95 nuclear reaction code. In this study, the excitation function of (α,xn) reactions on 237Np and 238Pu has been determined by invoking the Jeukenne-Lejeune-Mahaux-Bruyeres Optical model potential. The microscopic nuclear level density from Hilaire's combinatorial table is used to calculate the nuclear level density. Also, the excitation function has been evaluated by using the alpha potential of Watanabe folding approach with Koning-Delaroche spherical optical model potential and McFadden-Satchler potential. Furthermore, all the calculated cross-sections have been compared with the experimental results taken from EXFOR and the available evaluated cross-sections from TENDL2019 nuclear data library. The calculated cross sections using Jeukenne-Lejeune-Mahaux-Bruyeres Optical model potential together with microscopic nuclear level density from Hilaire's combinatorial table incorporating the Skyrme-Hartree-Fock-Bogoliubov calculation results in good correspondence with the experimental values from EXFOR.

Structural formation of multifunctional NiMoO4 nanorods for thermoelectric applications.

We report on the synthesis and characterization of NiMoO4 (NMO) nanorods via the hydrothermal method. The High-Resolution Scanning Electron Microscopy (HRSEM) image reveals the nanorod morphology of NMO. The formation of mixed phase α,ß-NMO is confirmed and the crystallite size of the nanorods is measured to be 40 nm from the XRD data. The structural formation of NMO is confirmed by Raman, FTIR, and XPS. The content of Ni, Mo and O was identified from XPS. NMO is optically active in the visible region with the band gap of 3.085 eV. The presence of four oxygen anions in the chemical formula gives the maximum electrical resistivity of 102 Ω m at 313 K and the material exhibits n-type semiconducting nature which is observed through Seebeck measurement and the Hall coefficient. The n-type semiconducting properties are observed due to the material being richer in Mo than Ni. The attained maximum Seebeck value of -159.723 µV K-1 at 513 K is comparable with that of other good thermoelectric materials at low temperatures. A decrease in the value of thermal conductivity was observed as a function of increasing temperature; NMO has the minimum thermal conductivity of 3.851 W m-1 K-1 at 513 K.

Crystal structure of (4-chloro-phen-yl)(4-methyl-piperidin-1-yl)methanone.

The title compound, C13H16ClNO, contains a methyl-piperidine ring in the stable chair conformation. The mean plane of the twisted piperidine ring subtends a dihedral angle of 39.89 (7)° with that of the benzene ring. In the crystal, weak C-H⋯O inter-actions link the mol-ecules along the a-axis direction to form infinite mol-ecular chains. H⋯H inter-atomic inter-actions, C-H⋯O inter-molecular inter-actions and weak dispersive forces stabilize mol-ecular packing and form a supra-molecular network, as established by Hirshfeld surface analysis.

Enhancing the thermoelectric power factor of nanostructured ZnCo2O4 by Bi substitution.

Bi x ZnCo2-x O4 (0 ≤ x ≤ 0.2) nanoparticles with different x values have been prepared by the sol-gel method; the structural, morphological, thermal and thermoelectric properties of the prepared nanomaterials are investigated. XRD analysis confirms that Bi is completely dissolved in the ZnCo2O4 lattice till the x values of ≤0.1 and the secondary phase of Bi2O3 is formed at higher x value (x > 0.1). The synthesized nanomaterials are densified and the thermoelectric properties are studied as a function of temperature. The electrical resistivity of the Bi x ZnCo2-x O4 decreased with x value and it fell to 4 × 10-2 Ω m for the sample with x value ≤ 0.1. The Seebeck coefficient value increased with the increase of Bi substitution till the x value of 0.1 and decreased for the sample with higher Bi content (x ≤ 0.2) as the resistivity of the sample increased due to secondary phase formation. With the optimum Seebeck coefficient and electrical resistivity, Bi0.1ZnCo1.9O4 shows the high-power factor (α 2 σ 550 K) of 2.3 µW K-2 m-1 and figure of merit of 9.5 × 10-4 at 668 K respectively, compared with other samples. The experimental results reveal that Bi substitution at the Co site is a promising approach to improve the thermoelectric properties of ZnCo2O4.

Enhancing effects of Te substitution on the thermoelectric power factor of nanostructured SnSe1-xTex.

Nanostructured SnSe1-xTex (0 < x < 0.2) was prepared by the planetary ball milling method. The prepared materials were studied by various analytical techniques. XRD analysis shows the pure phase of SnSe when x ≤ 0.1 and the secondary phase of SnTe was observed when x ≥ 0.1, possibly due to the low solid solubility limit of Te in SnSe. FESEM images revealed that the grain sizes of all the samples were in the range of 100 to 500 nm. TEM images showed the grain structures, sizes and grain boundaries of the samples. XPS analysis confirmed the incorporation of Te in SnSe1-xTex and the binding states of the elements in the samples. The samples were made into pellets and sintered at high temperature. The electrical resistivity of the SnSe1-xTex pellets decreased by up to two orders of magnitude as the x value increased in the samples. Concomitantly, the Seebeck coefficient of the SnSe1-xTex samples decreased drastically as the x value increased in the samples. A power factor (PF) of 102.8 µW K-2 m-1 was obtained for the SnSe0.9Te0.1 sample at 550 K, which is higher than the reported values for SnSe and SnSe1-xTex. When substituting Se with Te, the band structure of SnSe changes, which significantly enhances the thermoelectric PF of SnSe1-xTex for x ∼ 0.1. The PF decreased when the x value was increased further (x ≥ 0.1), possibly due to the precipitation of the SnTe phase. These experimental results demonstrate that the addition of a reasonable amount of Te is a promising approach for improving the thermoelectric properties of SnSe.

The theoretical and experimental vibrational studies of thiourea and silver nitrate (2:1) complex.

The theoretical and experimental vibrational studies for poly thiourea silver nitrate (2:1) complex using DFT method are performed on the basis of experimental data. During the geometry optimization process one equilibrium structure was found. The Mulliken charges, harmonic vibrational frequencies, Infrared and Raman intensities were calculated on the basis of quantum chemical density functional calculations using firefly (PC GAMESS) Version 7.1G. The clear - cut assignments of observed bands are performed on the basis of potential energy distribution (PED) analysis. Highest Occupied Molecular Orbital (HOMO) and the Lowest Occupied Molecular Orbital (LUMO) are obtained and graphically illustrated with minimum energy. The energy difference between HOMO and LUMO is analyzed. The other molecular properties like molecular electrostatic potential, Mulliken charges and thermodynamic properties of the title compound have also been calculated.

Crystal structure of (E)-1-(1-hy-droxy-naphthalen-2-yl)-3-(2,3,4-tri-meth-oxy-phen-yl)prop-2-en-1-one.

The title compound, C22H20O5, is composed of a hy-droxy-naphthyl ring and a tri-meth-oxy-phenyl ring [the planes of which are inclined to one another by 21.61 (10)°] bridged by an unsaturated prop-2-en-1-one group. The mean plane of the prop-2-en-1-one group [-C(=O)-C=C-] is inclined to that of the naphthyl system and benzene rings by 3.77 (14) and 18.01 (16)°, respectively. There is an intra-molecular O-H⋯O hydrogen bond present forming an S(6) ring motif. In the crystal, inversion-related mol-ecules are linked by a slipped-parallel π-π inter-action [inter-centroid distance = 3.8942 (13) Å, inter-planar distance = 3.478 (9) Šand slippage = 1.751 Å], and stack along the [101] direction. There are no other significant inter-molecular inter-actions present.

Crystal structure of 8-hy-droxy-quinolin-ium 2-carboxy-6-nitro-benzoate mono-hydrate.

In the title hydrated salt, C9H8NO(+)·C8H4NO6 (-)·H2O, the deprotonated carboxyl-ate group is almost normal to its attached benzene ring [dihedral angle = 83.56 (8)°], whereas the protonated carboxyl-ate group is close to parallel [dihedral angle = 24.56 (9)°]. In the crystal, the components are linked by N-H⋯O and O-H⋯O hydrogen bonds, generating [001] chains. The packing is consolidated by C-H⋯O and π-π [centroid-to-centroid distances = 3.6408 (9) and 3.6507 (9) Å] inter-actions, which result in a three-dimensional network.

Crystal structure of quinolinium 2-carboxy-6-nitro-benzoate monohydrate.

In the anion of the title hydrated mol-ecular salt, C9H8N(+)·C8H4NO6 (-)·H2O, the protonated carboxyl and nitro groups makes dihedral angles of 27.56 (5) and 6.86 (8)°, respectively, with the attached benzene ring, whereas the deprotonated carb-oxy group is almost orthogonal to it with a dihedral angle of 80.21 (1)°. In the crystal, the components are linked by O-H⋯O and N-H⋯O hydrogen bonds, generating [001] chains. The packing is consolidated by weak C-H⋯N and C-H⋯O inter-actions as well as aromatic π-π stacking [centroid-to-centroid distances: 3.7023 (8) & 3.6590 (9)Å] inter-actions, resulting in a three-dimensional network.

Structural and vibrational spectroscopic studies on charge transfer and ionic hydrogen bonding interactions of melaminium benzoate dihydrate.

Single crystals of melaminium benzoate dihydrate (MBDH) have been grown from aqueous solution by the slow solvent evaporation method at room temperature. Crystalline nature of the grown crystal has been confirmed by X-ray powder diffraction studies. The optimized geometry, frequency and intensity of the vibrational bands of MBDH were obtained by the Hartree-Fock and density functional theory using B3LYP/cam-B3LYP with 6-311++G(d,p) basis set. The harmonic vibrational frequencies were calculated and the scaled values have been compared with the experimental FT-IR and FT-Raman spectral values. The obtained vibrational wavenumbers and optimized geometric parameters are found to be in good agreement with the experimental data. UV-Visible spectrum was recorded in the region 200-400 nm and the electronic properties, HOMO-LUMO energies and other related electronic parameters are calculated. The isotropic chemical shifts computed by (1)H and (13)C NMR analysis also show good agreement with experimental observation. Natural bond orbital (NBO) analysis has been performed on MBDH compound to analyze the stability of the molecule arising from hyperconjugative interactions and charge delocalization. Molecular electrostatic potential surface (MEP) has also been performed by DFT/cam-B3LYP method with 6-311++G(d,p) basis set. Differential scanning calorimetric measurements performed on the powder sample indicate the phase transition point approximately at 368 and 358K for heating and cooling, respectively.

Growth, crystalline perfection, spectral and optical characterization of a novel optical material: l-tryptophan p-nitrophenol trisolvate single crystal.

l-tryptophan p-nitrophenol trisolvate (LTPN), an organic nonlinear optical material was synthesized using ethanol-water mixed solvent and the crystals were grown by a slow solvent evaporation method. The crystal structure and morphology were studied by single crystal X-ray diffraction analysis. The crystalline perfection of the LTPN crystal was analyzed by high-resolution X-ray diffraction study. The molecular structure of the crystal was confirmed by observing the various characteristic functional groups of the material using vibrational spectroscopy. The cut-off wavelength, optical transmission, refractive index and band gap energy were determined using UV-visible data. The variation of refractive index with wavelength shows the normal behavior. The second harmonic generation of the crystal was confirmed and the efficiency was measured using Kurtz Perry powder method. Single and multiple shot methods were employed to measure surface laser damage of the crystal. The photoluminescence spectral study revealed that the emission may be associated with the radiative recombination of trapped electrons and holes. Microhardness measurements revealed that LTPN belongs to a soft material category.

Crystal structure of bis[4-(di-methyl-amino)-pyridinium] bis(2-nitro-benzoate) trihydrate.

The title salt, 2C7H11N2 (+)·2C7H4NO4 (-)·3H2O, crystallized with two anions and two cations in the asymmetric unit, together with three water mol-ecules. Both 4-di-methyl-amino-pyridinium cations are protonated at their pyridine N atoms with the plane of the N(CH3)2 hetero atoms inclined to the pyridine ring by 4.5 (2) and 1.4 (2)°. In the 2-nitro-benzoate anions, the carboxyl and nitro groups are inclined to their respective benzene rings by 77.1 (3) and 20.0 (3)°, and 75.8 (2) and 20.9 (3)°. In the crystal, the anions are linked via O-H⋯O hydrogen bonds involving the water mol-ecules, forming chains along [100]. The cations are linked to these chains by N-H⋯O hydrogen bonds. The chains are linked via C-H⋯O hydrogen bonds and C-H⋯π and π-π inter-actions [inter-centroid distances range from 3.617 (1) to 3.851 (1) Å], forming a three-dimensional structure.

Studies on crystal growth, vibrational, optical, thermal and dielectric properties of new organic nonlinear optical crystal: Bis (2,3-dimethoxy-10-oxostrychnidinium) phthalate nonahydrate single crystal.

In this paper, we report the synthesis, growth and characterization of a new organic NLO single crystal of Bis (2,3-dimethoxy-10-oxostrychnidinium) phthalate nonahydrate, for the first time. The single crystal XRD study reveals that the crystal belongs to monoclinic system. The molecular structure and the nature of the vibrations were identified by vibrational and NMR spectroscopic studies. The UV absorption edge was found to be 330nm with a wide optical transmittance window covering the visible region. The crystal exhibits physicochemical stability upto 90.56°C. Various thermodynamic parameters were calculated from the TG data. The Kurtz powder second harmonic generation revealed that the SHG efficiency of the grown crystal was about 2.8 times that of KDP and was found to be phase matchable. The measured low value of birefringence indicates its suitability for NLO devices. The PL spectrum exhibited two peaks (355 and 406nm) due to the donation of protons from carboxylic acid to quartenium nitrogen. The dielectric behavior of the grown crystal was analyzed for different frequencies at different temperatures.

(E)-1-[2-(2-Nitro-styr-yl)-1-phenyl-sulfonyl-1H-indol-3-yl]propan-1-one.

In the title compound, C25H20N2O5S, the phenyl ring makes dihedral angles of 89.88 (8) and 13.98 (8)°, respectively, with the indole ring system and the nitro-benzene ring. The dihedral angle between the indole ring system and the nitro-benzene ring is 88.48 (11)°. The mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O inter-action. In the crystal, π-π inter-actions, with centroid-centroid distances of 3.6741 (18) and 3.8873 (17) Å, link the mol-ecules into layers parallel to the ab plane.

(E)-2-Bromo-1-[2-(2-nitro-styr-yl)-1-phenyl-sulfonyl-1H-indol-3-yl]ethanone.

In the title compound C24H17BrN2O5S, the phenyl ring makes dihedral angles of 85.4 (2) and 8.8 (2)° with the indole ring system and the nitro-benzene ring, respectively, while the indole ring system and nitrobenzene ring make a dihedral angle of 80.1 (2)°. In the crystal, weak C-H⋯O inter-actions link the mol-ecules, forming a two-dimensional network parallel to the bc plane.

Structure and vibrational spectra of melaminium bis(trifluoroacetate) trihydrate: FT-IR, FT-Raman and quantum chemical calculations.

Melaminium bis(trifluoroacetate) trihydrate (MTFA), an organic material has been synthesized and single crystals of MTFA have been grown by the slow solvent evaporation method at room temperature. X-ray powder diffraction analysis confirms that MTFA crystal belongs to the monoclinic system with space group P2/c. The molecular geometry, vibrational frequencies and intensity of the vibrational bands have been interpreted with the aid of structure optimization based on density functional theory (DFT) B3LYP method with 6-311G(d,p) and 6-311++G(d,p) basis sets. The X-ray diffraction data have been compared with the data of optimized molecular structure. The theoretical results show that the crystal structure can be reproduced by optimized geometry and the vibrational frequencies show good agreement with the experimental values. The nuclear magnetic resonance (NMR) chemical shift of the molecule has been calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. HOMO-LUMO, and other related molecular and electronic properties are calculated. The Mulliken and NBO charges have also been calculated and interpreted.

Vibrational, DFT, thermal and dielectric studies on 3-nitrophenol-1,3,5-triazine-2,4,6-triamine (2/1).

A new organic-organic salt, 3-nitrophenol-1,3,5-triazine-2,4,6-triamine (2/1) (3-NPM) has been synthesized by slow evaporation technique at room temperature. Single crystal X-ray diffraction analysis reveals that 3-NPM crystallizes in orthorhombic system with centrosymmetric space group Pbca and the lattice parameters are a=15.5150(6) Å, b=12.9137(6) Å, c=17.8323(6) Å, α=ß=γ=90° and V=3572.8(2)(Å)(3). The geometry, fundamental vibrational frequencies are interpreted with the aid of structure optimization and normal coordinate force field calculations based on density functional theory (DFT) B3LYP/6-311G(d,p) method. IR and Raman spectra of 3-NPM have been recorded and analyzed. The complete vibrational assignments are made on the basis of potential energy distribution (PED). The electric dipole moment, polarizability and the first order hyperpolarizability values of the 3-NPM have been calculated. (1)H and (13)C NMR chemical shifts are calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP method with 6-311G (d,p) basis set. Moreover, molecular electrostatic potential (MEP) and thermodynamic properties are performed. Mulliken and Natural charges of the title molecule are also calculated and interpreted. Thermal decomposition behavior of 3-NPM has been studied by means of thermogravimetric analysis. The dielectric measurements on the powdered sample have been carried out and the variation of dielectric constant and dielectric loss at different frequencies of the applied field has been studied and the results are discussed in detail.

Structural, optical, electron paramagnetic, thermal and dielectric characterization of chalcopyrite.

Chalcopyrite (CuFeS2) a variety of pyrite minerals was investigated through spectroscopic techniques and thermal analysis. The morphology and elemental analysis of the chalcopyrite have been done by high resolution SEM with EDAX. The lattice parameters were from the powder diffraction data (a=5.3003±0.0089 Å, c=10.3679±0.0289 Å; the volume of the unit cell=291.266 Å(3) with space group I42d (122)). The thermal decomposition behavior of chalcopyrite was studied by means of thermogravimetric analysis at three different heating rates 10, 15 and 20 °C/min. The values of effective activation energy (Ea), pre-exponential factor (ln A) for thermal decomposition have been measured at three different heating rates by employing Kissinger, Kim-Park and Flynn-Wall methods. Dielectric studies at different temperatures have also been carried out and it was found that both dielectric constant and dielectric loss decreases with the increase of frequency.

Structure, crystal growth, optical and mechanical studies of poly bis (thiourea) silver (I) nitrate single crystal: a new semi organic NLO material.

A new semi organic non linear optical polymeric crystal, bis (thiourea) silver (I) nitrate (TuAgN) with dimension 8×7×1.5 mm(3) has been successfully grown from aqueous solution by slow evaporation solution technique. Single crystal X-ray diffraction study reveals that the crystal belongs to orthorhombic system with non centrosymmetric space group C2221. The crystalline perfection of the crystal was analyzed by high resolution X-ray diffraction (HRXRD) rocking curve measurements. Functional groups present in the crystal were analyzed qualitatively by infrared and Confocal Raman spectral analysis. Effects due to coordination of thiourea with metal ions were also discussed. Optical absorption study on TuAgN crystal shows the minimum absorption in the entire UV-Vis region and the lower cut off wavelength of TuAgN is found to be 318 nm. Thermal analysis shows that the material is thermally stable up to 180°C. The mechanical strength and its parameters of the grown crystal were estimated by Vicker's microhardness test. The second harmonic generation (SHG) efficiency of the crystal was measured by Kurtz's powder technique infers that the crystal has nonlinear optical (NLO) efficiency 0.85 times that of KDP.

(Naphthalen-1-yl){2-[(5,6,7,8-tetrahydronaphthalen-2-yl)carbonyl]phenyl}methanone.

The title compound C28H22O2, basically consists of three ring systems, viz. a central benzene ring, with a lateral napthalene group to which it subtends a dihedral angle of 66.56 (4)° and a tetra-hydro-pyran ring exhibiting a half-chair conformation. The mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O inter-action, while the crystal packing features weak C-H⋯π contacts.