<?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%">Shaikh, Maulali H.</style></author><author><style face="normal" font="default" size="100%">Ramekar, V. Rohan</style></author><author><style face="normal" font="default" size="100%">Jawoor, Shailaja</style></author><author><style face="normal" font="default" size="100%">Dash, Soumya R.</style></author><author><style face="normal" font="default" size="100%">Birajadar, Rajkumar S.</style></author><author><style face="normal" font="default" size="100%">Pawal, Sandip B.</style></author><author><style face="normal" font="default" size="100%">Thenmani, Nandakumar</style></author><author><style face="normal" font="default" size="100%">Vanka, Kumar</style></author><author><style face="normal" font="default" size="100%">Chikkali, Samir H.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Designing of imine thiophene-ligated metal-complexes and implication in ethylene polymerization</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Macromolecular Science Part A-Pure and Applied Chemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cr-complexes</style></keyword><keyword><style  face="normal" font="default" size="100%">DFT</style></keyword><keyword><style  face="normal" font="default" size="100%">high-density polyethylene</style></keyword><keyword><style  face="normal" font="default" size="100%">Imine thiophene ligand</style></keyword><keyword><style  face="normal" font="default" size="100%">Polyethylene</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2024</style></year><pub-dates><date><style  face="normal" font="default" size="100%">SEP</style></date></pub-dates></dates><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;
	Polyethylene is the single largest volume polymer produced globally using Ziegler-type catalysts. Numerous modifications have been reported in search of a better catalyst that can control molecular weight, polydispersity, and branching. In our attempts to identify a suitable imine thiophene-ligated chromium complex, we examined 9 different titanium complexes computationally. The DFT investigations considered barriers for insertion, propagation, and termination by beta-H elimination or chain transfer, and identified N-(4-methoxyphenyl)-2-phenyl-1-(thiophen-2-yl)ethan-1-imine(L9) as the most suitable ligand. Subsequently, L9 was prepared in good yield (70%) by condensing 2-phenyl-1-(thiophen-2-yl)ethan-1-one with 4-methoxyaniline. Ligand L9 was treated with early transition metal precursors (Ti, Cr, Zr) to generate a homogenous catalyst. The identity of these catalysts was unambiguously ascertained using a combination of NMR, ICP, FT-IR, UV-Vis spectroscopy, and ESI-MS. The performance of L9-ligated titanium complex [Cat.1] was examined in ethylene polymerization using MMAO as a co-catalyst. Insertion of ethylene was tracked using high-pressure NMR experiments and Cat.1 was found to be active in the polymerization. Ethylene polymerization conditions were optimized to obtain high activity and molecular weight polyethylene. The chromium complex [Cat.2] outperformed the Ti and Zr-derived catalysts with the highest TOF of 6294 mol of PE/mol of Cr/h. Cat.2 produced high molecular weight, high-density polyethylene.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Article; Early Access</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%">&lt;p&gt;
	2.5&lt;/p&gt;
</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%">V. Bodkhe, Dnyaneshwar</style></author><author><style face="normal" font="default" size="100%">Patel, Ketan</style></author><author><style face="normal" font="default" size="100%">Shaikh, Maulali H.</style></author><author><style face="normal" font="default" size="100%">Kaulage, Sandeep H.</style></author><author><style face="normal" font="default" size="100%">Mahajan, Digvijay</style></author><author><style face="normal" font="default" size="100%">Pol, V. Harshawardhan</style></author><author><style face="normal" font="default" size="100%">Chikkali, Samir H.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Steric-bulk directed polymerization of ethylene to disentangled ultra-high molecular weight polyethylene</style></title><secondary-title><style face="normal" font="default" size="100%">European Polymer Journal</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Metal catalysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenoxy-imine ligand</style></keyword><keyword><style  face="normal" font="default" size="100%">Polyethylene</style></keyword><keyword><style  face="normal" font="default" size="100%">Titanium complexes</style></keyword><keyword><style  face="normal" font="default" size="100%">uHMWPE</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2026</style></year><pub-dates><date><style  face="normal" font="default" size="100%">JUN</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">253</style></volume><pages><style face="normal" font="default" size="100%">114762</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 electron-withdrawing pentafluorophenyl phenoxy-imine-derived titanium complexes are known to produce ultrahigh molecular weight polyethylene (UHMWPE). However, cyclohexyl phenoxy-imine-derived zirconium complexes have been reported to produce low molecular weight polyethylene. The disparity between the two types of polyethylenes and the two types of catalysts can be bridged if a titanium complex bearing sterically bulky groups is made to produce UHMWPE. We report steric bulk-directed cyclohexyl phenoxy-imine titaniumcatalyzed synthesis of UHMWPE in a disentangled state. The influence of steric bulk in a phenoxy-imine-cyclohexyl ligand framework on titanium complex formation and subsequent ethylene polymerization was investigated through a combined computational and experimental approach. Density functional theory (DFT) and buried volume analyses indicated that increasing steric demand from -H to -Me to -tert-Bu substituents enhances the buried volume around the metal center, potentially favoring high molecular weight polyethylene formation. Guided by these insights, three ligands, L1-L3, were synthesized in excellent yields and fully characterized, including by single-crystal X-ray diffraction. Treatment of L1-L3 with a titanium precursor produced respective complexes, Cat.1-Cat.3, in good yields. These were characterized by NMR, IR, MS, and single-crystal X-ray diffraction. Upon activation with various co-catalysts [methyl aluminoxane (MMAO), triisobutylaluminum (TIBA), and tetrakis (pentafluoro phenyl) borate (BT)], these complexes initiated ethylene polymerizations. The catalytic activity increased from Cat.1 to Cat.2 with growing steric bulk, but decreased for the highly hindered Cat.3, likely due to restricted monomer access to the active site. Among the three, Cat.2, in combination with MMAO, showed the best performance under optimized conditions and produced ultrahigh molecular weight polyethylene (UHMWPE&lt;/p&gt;
</style></abstract><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%">&lt;p&gt;
	6.8&lt;/p&gt;
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