<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sankar, M.</style></author><author><style face="normal" font="default" size="100%">Nair, C. Madhavan</style></author><author><style face="normal" font="default" size="100%">Murty, K. V. G. K.</style></author><author><style face="normal" font="default" size="100%">Manikandan, Palanichamy</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Transesterification of cyclic carbonates with methanol at ambient conditions over tungstate-based solid catalysts</style></title><secondary-title><style face="normal" font="default" size="100%">Applied Catalysis A-General</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dimethyl carbonate</style></keyword><keyword><style  face="normal" font="default" size="100%">ethylene carbonate</style></keyword><keyword><style  face="normal" font="default" size="100%">heterogeneous catalyst</style></keyword><keyword><style  face="normal" font="default" size="100%">Raman spectroscopy</style></keyword><keyword><style  face="normal" font="default" size="100%">sodium tungstate</style></keyword><keyword><style  face="normal" font="default" size="100%">transesterification</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">SEP</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">ELSEVIER SCIENCE BV</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">312</style></volume><pages><style face="normal" font="default" size="100%">108-114</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Dimethyl carbonate synthesis with 80 mol% yield is achieved through transesterification of ethylene carbonate with methanol at ambient conditions (RT and atmospheric pressure) using alkali and alkaline-earth tungstates as solid catalysts. The catalysts are efficient even at the sub-ambient temperatures. Reactions under CO2 pressure indicate that CO2 atmosphere retards the transesterification reaction completely below 100 degrees C. Experimental conditions of 150 degrees C and 3.4 MPa CO2 pressure are required to obtain maximum DMC yield of 71 mol%. Synthesis of DMC by one-pot synthesis using epoxide, CO2 and methanol is not as effective as that by two-step method with the present catalyst system. Raman and IR spectra of methanol-interacting tungstates indicate the formation of a methoxide ion species adsorbed at the catalyst surface as one possible reaction intermediates. (C) 2006 Elsevier B.V. All rights reserved.&lt;/p&gt;</style></abstract><work-type><style face="normal" font="default" size="100%">Article</style></work-type><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">4.012</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sankar, Meenakshisundaram</style></author><author><style face="normal" font="default" size="100%">Satav, Srikanth</style></author><author><style face="normal" font="default" size="100%">Manikandan, Palanichamy</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Transesterification of cyclic carbonates to dimethyl carbonate using solid oxide catalyst at ambient conditions: environmentally benign synthesis</style></title><secondary-title><style face="normal" font="default" size="100%">Chemsuschem</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">calcium</style></keyword><keyword><style  face="normal" font="default" size="100%">environmental chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">heterogeneous catalysis</style></keyword><keyword><style  face="normal" font="default" size="100%">transesterification zinc</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">MAY</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">5</style></number><publisher><style face="normal" font="default" size="100%">WILEY-V C H VERLAG GMBH</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY</style></pub-location><volume><style face="normal" font="default" size="100%">3</style></volume><pages><style face="normal" font="default" size="100%">575-578</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">5</style></issue><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">6.325</style></custom4></record></records></xml>