01639nas a2200277   4500008004100000022001400041245014200055210006900197260007300266300001200339490000800351520062700359653002100986653001901007653003701026653001901063653001701082653002001099653002201119653001901141653001701160100001901177700001901196700001701215856012901232       2005                        eng d  a1381-116900aFactors affecting activation and utilization of carbon dioxide in cyclic carbonates synthesis over Cu and Mn peraza macrocyclic complexes0 aFactors affecting activation and utilization of carbon dioxide i  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB  a199-2050 v2263 a<p>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.</p>10abenign synthesis10aCarbon dioxide10acatalysis by Cu and Mn complexes10aCO2 activation10aCO2 fixation10aCO2 utilization10acyclic carbonates10apolycarbonates10aspectroscopy1 aSrivastava, R.1 aBennur, T., H.1 aSrinivas, D.  uhttps://library.ncl.res.in/content/factors-affecting-activation-and-utilization-carbon-dioxide-cyclic-carbonates-synthesis-001626nas a2200265   4500008004100000022001400041245013300055210006900188260010600257300001400363490000700377520063300384653001501017653003101032653001701063653002201080653002701102653001101129653001901140653001801159100001901177700001701196700001801213856012901231       2006                        eng d  a0040-403900aSyntheses of polycarbonate and polyurethane precursors utilizing CO2 over highly efficient, solid as-synthesized MCM-41 catalyst0 aSyntheses of polycarbonate and polyurethane precursors utilizing  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJUN  a4213-42170 v473 a<p>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.</p>10acarbamates10acarbon dioxide utilization10aCO2 fixation10acyclic carbonates10aeco-friendly processes10aMCM-4110apolycarbonates10apolyurethanes1 aSrivastava, R.1 aSrinivas, D.1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/syntheses-polycarbonate-and-polyurethane-precursors-utilizing-co2-over-highly-efficient-0