http://nopr.niscair.res.in/handle/123456789/12947 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/12996 Title: A structural study on the cubic crystalline modification of [Cp₆Ti₆O₈][Bu₃Sn₃S₃(SH)₃Cl]₂ <br/> <br/>Authors: Singh, Neetu; Bhattacharya, Subrato <br/> <br/>Abstract: Crystal and molecular structures of a cubic crystalline form of [Cp₆Ti₆O₈][Bu₃Sn₃S₃(SH)₃Cl]₂have been studied by single crystal X-ray diffraction. The cation, [Cp₆Ti₆O₈]²⁺is a cluster comprising an octahedron with six Ti(IV) atoms at the vertices. Each of the eight faces is capped by an oxygen atom. The cluster is electron deficient as it possesses 84 electrons only. The anion is a six membered ring (with alternated Sn and S atoms) having a chair conformation. The crystal undergoes a phase transition on cooling which has been monitored by X-ray diffraction studies. <br/> <br/>Page(s): 1592-1595 http://nopr.niscair.res.in/handle/123456789/12995 Title: Synthesis of nano-MgO and identification of the destructive product of its reaction with 2-chloroethyl phenyl sulfide <br/> <br/>Authors: Maddah, Bozorgmehr; Aminifar, Amir; Chalabi, Hossein <br/> <br/>Abstract: Nanocrystalline magnesium oxide has been prepared by the sol-gel method and characterized by X-ray diffraction, N₂-BET, SEM and infrared spectroscopic techniques. Results confirm the formation of nano-MgO materials with crystallite size in the range of 5-20 nm and surface area of 336-556 m²/g. The product has been tested as destructive adsorbent for the decontamination of (2-chloroethyl) phenyl sulfide, a mimic of bis(2-chloroethyl) sulfide ("HD" or mustard gas). Destructive adsorbent reaction has been carried out in heptane and methanol media and investigated by GC-FID and GC-MS techniques. Reaction rate in heptane is observed to be higher than in methanol. It seems that a nonpolar media aids material transfer to the reactive surface sites without blocking these sites. <br/> <br/>Page(s): 1587-1591 http://nopr.niscair.res.in/handle/123456789/12994 Title: Performance of <i>ab initio</i> and DFT methods in modeling Diels-Alder reactions <br/> <br/>Authors: Gayatri, Gaddamanugu <br/> <br/>Abstract: The performance of a range of computational methods in modeling Diels-Alder reactions of acyclic, cyclic and annelated dienes with ethylene has been assessed. The average asynchronicity values, mean, mean absolute deviation and standard deviation values with respect to activation and reaction energies are calculated and the preference for one method over the other is validated. While M05-2X generates less asynchronous transition states, more asynchronous transition states are obtained at M05 level amongst the methods considered. M05/6-311+G(d,p) is found to be adequate in modeling the Diels-Alder reactions involving acyclic systems. M05-2X method in combination with 6-311+G(d,p) basis set is found to be reliable to model the potential energy surface of cyclic systems. For modeling the reactions involving annelated dienes, the MPW1K method along with 6-311+G(d,p) basis set is found to be adequate. <br/> <br/>Page(s): 1579-1586 http://nopr.niscair.res.in/handle/123456789/12993 Title: Epoxidation of olefins catalyzed by manganese(II) complexes of Schiff base ligand having N2O coordination sphere <br/> <br/>Authors: Guha, Averi; Das, Debasis <br/> <br/>Abstract: Three mononuclear manganese(II) complexes having two N₂O coordination spheres have been examined as catalysts for epoxidation of (<i>E</i>)-stilbene and styrene using PhIO and NaOCl as terminal oxidants in four different solvents. The catalytic efficiency of the complexes are observed to be influenced not only by their own structural features but also by the nature of terminal oxidant, substrate as well as the solvents. Epoxidation proceeds with the formation of two different intermediates, O=Mn(IV)(L)(X) and Cl-O-Mn(II)(L)(X) [X=NO₃/SCN/N(CN)₂], in presence of PhIO and NaOCl respectively. Amongst the solvents, acetonitrile is found to be the most suitable. <br/> <br/>Page(s): 1574-1578