<?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%">Bennur, T. H.</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%">Factors affecting activation and utilization of carbon dioxide in cyclic carbonates synthesis over Cu and Mn peraza macrocyclic complexes</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Molecular Catalysis A - Chemical</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">benign synthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon dioxide</style></keyword><keyword><style  face="normal" font="default" size="100%">catalysis by Cu and Mn complexes</style></keyword><keyword><style  face="normal" font="default" size="100%">CO2 activation</style></keyword><keyword><style  face="normal" font="default" size="100%">CO2 fixation</style></keyword><keyword><style  face="normal" font="default" size="100%">CO2 utilization</style></keyword><keyword><style  face="normal" font="default" size="100%">cyclic carbonates</style></keyword><keyword><style  face="normal" font="default" size="100%">polycarbonates</style></keyword><keyword><style  face="normal" font="default" size="100%">spectroscopy</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">FEB</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">2</style></number><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%">226</style></volume><pages><style face="normal" font="default" size="100%">199-205</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The catalytic activities of several Cu and Mn aza complexes for cyclic carbonate synthesis from CO2 and epoxides are reported. The various factors affecting activation of CO2 by metal complexes and its utilization in cyclic carbonate synthesis have been investigated. Fr-IR, UV-vis and EPR spectroscopic investigations reveal that CO2 coordinates to Cu in eta(1)-C mode of coordination. Nature of the ligand and substitution influence the lability of metal-CO2 bonding. The differences in the catalytic activities are correlated with the mode and strength of CO2 binding. (C) 2004 Elsevier B.V. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><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%">3.958</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%">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%">Spectroscopic and catalytic properties of SBA-15 molecular sieves functionalized with acidic and basic moieties</style></title><secondary-title><style face="normal" font="default" size="100%">Microporous and Mesoporous Materials</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">aerial oxidation of terpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">CO2 utilization</style></keyword><keyword><style  face="normal" font="default" size="100%">cyclic carbonates synthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">epoxidation</style></keyword><keyword><style  face="normal" font="default" size="100%">functionalization with acidic and basic moieties</style></keyword><keyword><style  face="normal" font="default" size="100%">immobilization of Mn complexes</style></keyword><keyword><style  face="normal" font="default" size="100%">organo-functionalization of SBA-15</style></keyword><keyword><style  face="normal" font="default" size="100%">solid acid-base catalysts</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">SEP</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">1-2</style></number><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%">105</style></volume><pages><style face="normal" font="default" size="100%">170-180</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;SBA-15, grafted with Lewis acidic Ti4+ ions and basic amines (imidazole, guanine or adenine) exhibited high catalytic activity in the cycloaddition of CO2 to epoxides yielding selectively cyclic carbonate precursors of polycarbonates. In the second class of materials, the surface of SBA-15 was grafted with thiol or sulfonic acid functionalities. Mn(Salen)Cl was, then, covalently bound to these acidic groups. The resulting catalysts show enhanced chemo-, regio- and stereo-selective catalytic activity in the epoxidation of terpenes such as R-(+)limonene, alpha-pinene and Delta-carene with molecular oxygen. The acid-base properties of these modified SBA- 15 materials were investigated by temperature-programmed desorption and diffuse-reflectance infrared Fourier transform spectroscopy. Ammonia and pyridine were used as probe molecules for acidic sites and CO2 for basic sites. Acidic Ti sites activated epoxides and the grafted basic amines activated CO2. The simultaneous presence of both acidic and basic sites on amine/adenine-functionalized Ti-SBA-15 enabled synergistic enhancement in catalytic activity in the cycloaddition reaction of CO2 to epoxides. When Mn(Salen)Cl was immobilized on thiol or sulfonic acid-functionalized SBA-15, the oxidation state of Mn decreased from +3 to +2. The organo-acidic functional groups (thiol or sulfonic acid) axialk, coordinated to Mn ions modified the electronic structure of Mn ions enhancing the activity and selectivity of Mn(Salen) complexes in aerial oxidation reactions. (C) 2007 Elsevier Inc. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">1-2</style></issue><work-type><style face="normal" font="default" size="100%">Article</style></work-type><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">3.349</style></custom4></record></records></xml>