http://nopr.niscair.res.in/handle/123456789/7822 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/7830 Title: Kinetics and mechanism of silver(I) catalyzed oxidation of valine by cerium(IV) in acid perchlorate medium <br/> <br/>Authors: Yadav, M B; Devra, Vijay; Rani, Ashu <br/> <br/>Abstract: Kinetics of silver(I) catalyzed oxidation of valine with cerium(IV) has been studied in perchloric acid medium. A decrease in rate with increase in [Ce(IV)] is observed. The detailed quantitative analysis of this behavior is presented on the basis of dimerization of cerium(IV). The reaction exhibits fractional dependence on valine which is explained on the basis of formation of an adduct with silver(I). A plausible reaction mechanism is given and the rate law is derived as follows:<img src='/image/spc_char/formula.gif'> , where <i style="">k</i> is the observed second order rate constant. <br/> <br/>Page(s): 442-447 Mon, 29 Mar 2010 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/7829 Title: Electroluminescent characteristics of bis(5-chloro-8-hydroxyquinolinato)- zinc(II) complex <br/> <br/>Authors: Sharma, Anita; Singh, Devender; Kadyan, Partap S; Kumar, Amit; Singh, Kapoor; Chauhan, Gayatri; Singh, Ishwar <br/> <br/>Abstract: A zinc(II) complex with 5-chloro-8-hydroxyquinoline has been used as emitting material to produce yellow light. On excitation by UV light at 385 nm, thin film of the complex fluoresced at 550 nm. Multilayer organic electroluminescence devices fabricated using this fluorescent material produce emission with good chromaticity (CIE coordinates <i>x</i> = 0.313 and <i>y </i>= 0.576). Maximum luminance of 466 cd/m² is achieved when 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane is used as dopant in 4,4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl at 12 V. The devices show typical non-linear diode current-voltage characteristics under forward bias with the threshold voltage of 6V. The CIE coordinates are found to be independent of the operating voltage. <br/> <br/>Page(s): 448-451 Mon, 29 Mar 2010 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/7828 Title: Synthesis and structural characterization of 1-methylpiperazinediium tetrasulfidotungstate monohydrate <br/> <br/>Authors: Srinivasan, Bikshandarkoil R; Naik, Ashish R; Näther, Christian; Bensch, Wolfgang <br/> <br/>Abstract: The reaction of (NH₄)₂[WS₄] with 1-methylpiperazine results in the formation of 1-methylpiperazinediium tetrasulfidotungstate monohydrate,<b style=""> </b>in good yield. (Me-pipH₂)[WS₄]·H₂O has been characterized by elemental analysis, IR, Raman and UV-vis spectra and its crystal structure. The title compound crystallizes in the centrosymmetric monoclinic space group <i style="">P2₁/c</i> and its structure consists of a discrete, slightly distorted tetrahedral tetrasulfidotungstate anion, 1-methylpiperazinediium cation and lattice water, which are linked by five varieties of H-bonding interactions namely N-H···O, N-H···S, O-H···S, C-H···O and C-H···S. The lattice water links pairs of organic cations with pairs of [WS₄]^2- anions via N-H···O, O-H···S, and C-H···O bonds, while the cations and anions are linked via N-H···S, and C-H···S bonds. <br/> <br/>Page(s): 437-441 Mon, 29 Mar 2010 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/7827 Title: DFT study on the reaction of La (²D) with CH₃CHO <br/> <br/>Authors: Dai, Guoliang; Chen, Hao; Yan, Hua; Wang, Chuanfeng; Zhong, Aiguo <br/> <br/>Abstract: The reaction mechanism of the ground state (²D) La atom with CH₃CHO has been studied in detail by density functional theory. All the stationary points has been determined at the UB3LYP/ECP/ 6-311+G** level of theory. Single point UCCSD(T)/ECP/6-311+G** calculations have been used to get accurate values of energies. The titled reaction starts with the formation of a η²-CH₃CHO-metal complex followed by C−C, C−O, aldehyde C−H and methyl C−H activation. These reactions can lead to four products, i. e., LaCO+CH₄, HLaCH₃+CO, LaO+C₂H₄and LaCH₂CO+H₂. As the energies of the intermediates, transition states and products involved in the reaction lie below those of the reactants, La(²D) + CH₃CHO, (except TS₃₈, only 0.18 kcal/mol relative to the reactants), the reaction between La(²D) and CH₃CHO is expected to occur spontaneously over the doublet potential energy surface. The present results may be helpful in understanding the mechanism of the titled reaction and further experimental investigation of the reaction. <br/> <br/>Page(s): 431-436 Mon, 29 Mar 2010 22:58:59 GMT