<?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%">Kumawat, Jugal</style></author><author><style face="normal" font="default" size="100%">Gupta, Virendra Kumar</style></author><author><style face="normal" font="default" size="100%">Vanka, Kumar</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Nature of the active site in ziegler-natta olefin polymerization catalysis systems - a computational investigation</style></title><secondary-title><style face="normal" font="default" size="100%">European Journal of Inorganic Chemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Alkene polymerization</style></keyword><keyword><style  face="normal" font="default" size="100%">Density functional calculations</style></keyword><keyword><style  face="normal" font="default" size="100%">heterogeneous catalysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Insertion</style></keyword><keyword><style  face="normal" font="default" size="100%">Polymers</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year><pub-dates><date><style  face="normal" font="default" size="100%">OCT</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">29</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%">BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY</style></pub-location><pages><style face="normal" font="default" size="100%">5063-5076</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Pull quantum chemical calculations with density functional theory (DET) show that a principal role of donors in Ziegler-Nana (ZN) oh-din polymerization catalysts is to coordinate to the metal center at the active sites on the MgCl2 surface. Thereby, the behavior of the catalyst is modulated to favor insertion over termination and, thus, polymerization occurs. This is shown to be true for a range of different donors. The calculations indicate that active sites that feature anionic chloride ligands at the titanium center (the conventional model for the active site) would lead to lower-molecular-weight riolymers. If an -OC2H5 group were present instead of a chloride ligand, the active site would much more effectively produce long chain polymers. Therefore, the current work provides important new insights into the nature of the ZN polymerization process.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">29</style></issue><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">2.39</style></custom4></record></records></xml>