http://nopr.niscair.res.in/handle/123456789/6094 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/6126 Title: Synthesis, characterization and X-ray single crystal studies of mono-<i style="">n</i>-butyltin(IV) dichloride complex of pyruvic acid- 2-pyridylhydrazone [<i style="">n</i>-BuSnCl₂(PAP)] <br/> <br/>Authors: Affan, M A; Foo, I P P; Fasihuddin, B A; Hapipah, M A; Shamsuddin, M <br/> <br/>Abstract: Mono-<i style="">n</i>-butyltin(IV) dichloride complex with the general formula [<i style="">n-</i>BuSnCl₂(PAP)] has been synthesized by direct reaction of <i style="">n-</i>BuSnCl₃ with pyruvic acid-2-pyridylhydrazone in the presence of KOH in equimolar ratio in absolute methanol under nitrogen atmosphere. Both, the ligand as well as the complex, have been characterized by elemental analyses, UV-visible, IR, ¹H NMR spectral and X-ray diffraction studies. [<i style="">n-</i>BuSnCl₂(PAP)] is nonelectrolytic in nature. Single crystal X-ray diffraction studies indicate that [<i style="">n-</i>BuSnCl₂(PAP)], is six-coordinated and adopts a distorted octahedral configuration with the coordination via carboxylic-O, imine-N and pyridyl-N atoms from the ligand. The crystal system of [<i style="">n-</i>BuSnCl₂(PAP)] is tetragonal with space group I4₁/<i style="">a</i> and the unit cell dimensions: <i style="">a</i> = 16.602(3)Å, <i style="">b =</i> 16.602(3)Å, <i style="">c</i> = 23.922(8)Å, <i style=""><img src='/image/spc_char/alpha.gif'> </i> = <i style=""><img src='/image/spc_char/beta.gif'></i> = <i style=""><img src='/image/spc_char/gamma2.gif'>=</i> 90˚. <br/> <br/>Page(s): 1388-1393 http://nopr.niscair.res.in/handle/123456789/6125 Title: Effect of polar dopants on structure of emission spectrum of crystalline anthracene powders <br/> <br/>Authors: Gharge, M N; Bhattar, S L; Kolekar, G B; Patil, S R <br/> <br/>Abstract: The effect of polar dopants on the spectral properties of crystalline anthracene is studied as a function of concentration by steady state fluorescence spectroscopy. The dopant is a fluorescent 9-vinylanthracene. The incorporation of the dopant not only quenches the fluorescence but also changes the structure of emission of anthracene. The higher dopant concentration induces significant enhancement in the intensity of low energy (0←1) vibronic band at the expense of high energy (0←0) band and wavelength of maximum emissions is shifted from 427 nm to 446 nm. The characteristic monomer and excimer emission of dopant are not observed even at higher concentration in the fluorescence spectra of doped anthracene. This observation rules out the possibility of excitation energy transfer from anthracene to dopant molecule. The shift in structure of emission of anthracene has been attributed to the local electric field generated by the polar dopant which is acting across the anthracene molecule and induces the changes both in the molecular vibrational levels and in transition dipoles. This effect is similar to solid state solvation effect and favors transition to the higher vibrational level of the ground state. <br/> <br/>Page(s): 1383-1387 http://nopr.niscair.res.in/handle/123456789/6124 Title: Effect of surface area, pore volume and particle size of P25 titania on the phase transformation of anatase to rutile <br/> <br/>Authors: Raj, K Joseph Antony; Viswanathan, B <br/> <br/>Abstract: The effect of calcination on P25 titania at different temperatures has been studied by XRD, nitrogen adsorption-desorption isotherm, BET-surface area, pore volume, pore size, particle size and crystallite size in order to understand the conversion of anatase phase to rutile phase. The fraction of anatase and rutile has been determined using XRD. Although the crystallinity remains the same, the phase change of anatase to rutile is inevitable with temperature. The isotherms show the non-porous characteristics of the P25 samples. In addition, nitrogen adsoption by the samples decreased appreciably with crystallinity. The pore volume and BET surface area show a large decrease at 900^oC. The particle size, crystallite size, and pore size show an increasing trend with increase in temperature. Analysis of the physical characteristics indicates that P25 titania samples can be used for catalytic applications at less than 500^oC. <b style=""></b> <br/> <br/>Page(s): 1378-1382 http://nopr.niscair.res.in/handle/123456789/6123 Title: Synthesis, characterization and superoxide dismutase activity of some four coordinated copper(II) complexes <br/> <br/>Authors: Patel, R N <br/> <br/>Abstract: Mixed ligand copper(II) complexes, viz.<i style="">,</i> [Cu(Br-SAA)(ImH)]<b style="">,</b> [Cu(Br-SAA)(MeImH)], [Cu(Br-SAA)(EtImH)], [Cu(Br-SAA)(BenzImH)] and [Cu(Br-SAA)(MebenzImH)], where Br-SAA = 5-bromosalicylideneanthranilic acid, ImH = imidazole, MeImH = 2-methyl imidazole, EtImH = 2-ethyl imidazole, BenzImH = benzimidazole, MebenzImH = 2-methyl benzimidazole are synthesized and characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, FAB mass, IR, electronic, EPR spectral and cyclic voltammetric studies. The complex [Cu(Br-SAA)(ImH)] structurally characterized by single crystal X-ray crystallography, crystallizes in the triclinic space group <i style="">P-1</i> with unit cell parameters: <i style="">a</i> = 3.7875(15)Å, <i style="">b</i> = 10.6246(19)Å, <i style="">c</i> = 19.977(3)Å, <img src='/image/spc_char/alpha.gif'> = 96.565(14)°_, <img src='/image/spc_char/beta.gif'> = 94.45(2)°_, <img src='/image/spc_char/gamma.gif'> = 92.32 (2)° and Z = 2. The one electron paramagnetic complexes show a <i style="">d-d</i> band near 700 nm in DMSO and a cyclic voltammetric response due to Cu(II)/Cu(I) couple. The complexes show the presence of a distorted square planar CuN₂O₂ coordination geometry. Superoxide dismutase activity of these complexes have also been examined <br/> <br/>Page(s): 1370-1377