<?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><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%">Agrawal, Nisha K.</style></author><author><style face="normal" font="default" size="100%">Dash, Soumya R.</style></author><author><style face="normal" font="default" size="100%">Vanka, Kumar</style></author><author><style face="normal" font="default" size="100%">Nethaji, Munirathinam</style></author><author><style face="normal" font="default" size="100%">Jagirdar, Balaji R.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Reactivity of four coordinate iridium complex towards hydrogen: an experimental and computational study</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Organometallic Chemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Hydrogenation</style></keyword><keyword><style  face="normal" font="default" size="100%">Insertion</style></keyword><keyword><style  face="normal" font="default" size="100%">iridium complex</style></keyword><keyword><style  face="normal" font="default" size="100%">isomerization</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidative addition</style></keyword><keyword><style  face="normal" font="default" size="100%">Reductive elimination</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2022</style></year><pub-dates><date><style  face="normal" font="default" size="100%">MAY</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">965</style></volume><pages><style face="normal" font="default" size="100%">122317</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;
	Reaction of a four coordinate, 16-electron Ir complex, [Ir-(iPr)4(POCOP)(PPh3)] (4 ) (((iPr)4)(POCOP= 2,6-bis(di-isopropyl phosphinito)benzene, kappa(3)-C6H3-1,3-[OP((iPr))(2)](2)), with H-2 resulted in an oxidative addition product, cis-dihydride complex, cis-[Ir(H)(2) ((iPr)4)(POCOP)(PPh3)] ( cis-5 ) presumably via the intermediacy of a sigma complex, [Ir(eta(2)-H-2)((iPr)4)(POCOP)(PPh3)]. The cis-dihydride complex completely isomerizes to the trans-dihydride complex trans-[Ir(H)(2) ((iPr)4)(POCOP)(PPh3)] ( trans-5 ) under ambient conditions in about 3 h. It was found that the steric and electronic features on the iridium center have significant influence on the approach of H-2 onto the metal center followed by oxidative addition and isomerization. The isomerization process was studied in detail and all the mechanistic aspects have been elucidated using a combination of both experimental work and computation. The cis-dihydride complex isomerizes to the trans-dihydride by compensating the trans influence of the strongly trans-directing hydride ligand. A mechanism involving the exchange of the position of PPh3 with a hydride ligand cis to itself via PPh3 dissociation and re-coordination thereby resulting in the formation of the trans-dihydride complex, has been proposed for the isomerization. The cis-dihydride was found to be a highly active catalyst for hydrogenation of ethy-lene. A competing reactivity study of cis-dihydride between isomerization versus insertion of C2H4 into the Ir-H bond, was studied experimentally and computationally. (c) 2022 Elsevier B.V. All rights reserved.&lt;/p&gt;
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	Foreign&lt;/p&gt;
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	2.345&lt;/p&gt;
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