<?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%">Srivastava, R.</style></author><author><style face="normal" font="default" size="100%">Srinivas, D.</style></author><author><style face="normal" font="default" size="100%">Ratnasamy, P.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Syntheses of polycarbonate and polyurethane precursors utilizing CO2 over highly efficient, solid as-synthesized MCM-41 catalyst</style></title><secondary-title><style face="normal" font="default" size="100%">Tetrahedron Letters</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">carbamates</style></keyword><keyword><style  face="normal" font="default" size="100%">carbon dioxide utilization</style></keyword><keyword><style  face="normal" font="default" size="100%">CO2 fixation</style></keyword><keyword><style  face="normal" font="default" size="100%">cyclic carbonates</style></keyword><keyword><style  face="normal" font="default" size="100%">eco-friendly processes</style></keyword><keyword><style  face="normal" font="default" size="100%">MCM-41</style></keyword><keyword><style  face="normal" font="default" size="100%">polycarbonates</style></keyword><keyword><style  face="normal" font="default" size="100%">polyurethanes</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%">JUN</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">25</style></number><publisher><style face="normal" font="default" size="100%">PERGAMON-ELSEVIER SCIENCE LTD</style></publisher><pub-location><style face="normal" font="default" size="100%">THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND</style></pub-location><volume><style face="normal" font="default" size="100%">47</style></volume><pages><style face="normal" font="default" size="100%">4213-4217</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;As-synthesized MCM-41 was used as a reusable, heterogeneous catalyst for the eco-friendly synthesis of cyclic carbonate precursors of polycarbonates via a cycloaddition reaction of CO2 with epoxides. This catalyst is also efficient for the synthesis of alkyl and aryl carbamate precursors of polyurethanes via the reaction of amines, CO2 and alkyl halides. Both these reactions were carried out under mild conditions and without using any solvent or co-catalyst. CO2 is utilized as a raw material replacement for toxic phosgene in the conventional synthesis of these chemicals. (c) 2006 Elsevier Ltd. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">25</style></issue><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%">2.347</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%">Hamza, A.</style></author><author><style face="normal" font="default" size="100%">Srinivas, D.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Selective oxidation of benzyl alcohol over copper phthalocyanine immobilized on MCM-41</style></title><secondary-title><style face="normal" font="default" size="100%">Catalysis Letters</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Copper phthalocyanine</style></keyword><keyword><style  face="normal" font="default" size="100%">EPR</style></keyword><keyword><style  face="normal" font="default" size="100%">MCM-41</style></keyword><keyword><style  face="normal" font="default" size="100%">Selective oxidation of benzyl alcohol</style></keyword><keyword><style  face="normal" font="default" size="100%">UV-visible spectroscopy</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">MAR</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">3-4</style></number><publisher><style face="normal" font="default" size="100%">SPRINGER</style></publisher><pub-location><style face="normal" font="default" size="100%">233 SPRING ST, NEW YORK, NY 10013 USA</style></pub-location><volume><style face="normal" font="default" size="100%">128</style></volume><pages><style face="normal" font="default" size="100%">434-442</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Copper phthalocyanine (CuPc) complexes immobilized on ``neat'' and Ti(4+) and Al(3+) containing MCM-41 mimic the functionality of metalloenzymes. These novel materials catalyze the oxidation of benzyl alcohol to selectively benzaldehyde at moderate temperatures using peroxides and molecular oxygen as oxidant. Electron paramagnetic resonance and X-ray photoelectron spectroscopic studies revealed that the acidity of the support (MCM-41) influences the electronic structure of the immobilized CuPc. On acidic supports a part of copper in CuPc got reduced from a ``formal'' +2 to +1 oxidation state. This reduction of copper in its oxidation state on different supports decreased in the order: Al-MCM-41 (Bronsted and strong Lewis acid sites) &amp;gt; MCM-41 (silanol sites) &amp;gt; Ti-MCM-41 (weak Lewis acid sites). A linear variation in catalytic activity with the concentration of Cu(1+) ions in different catalyst samples was observed. The study reveals that by suitably modifying the acidic properties of the support one can, in principle, fine-tune the electronic and catalytic properties of the active oxidation sites.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3-4</style></issue><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">1.907</style></custom4></record></records></xml>