Pd-iminocarboxylate complexes and their behavior in ethylene polymerization
Title | Pd-iminocarboxylate complexes and their behavior in ethylene polymerization |
Publication Type | Journal Article |
Year of Publication | 2020 |
Authors | Deshmukh, SS, Gaikwad, SR, Gonnade, RG, Pandole, SP, Chikkali, SH |
Journal | Chemistry-An Asian Journal |
Volume | 15 |
Issue | 3 |
Pagination | 398-405 |
Date Published | FEB |
Type of Article | Article |
ISSN | 1861-4728 |
Keywords | imine, Imine-carboxylate, Insertion polymerization, Pd complexes, Polyethylene |
Abstract | Designing co-catalyst-free late transition metal complexes for ethylene polymerization is a challenging task at the interface of organometallic and polymer chemistry. Herein, a set of new, co-catalyst-free, single-component catalytic systems for ethylene polymerization have been unraveled. Treatment of anthranilic acid with various aldehydes produced four iminocarboxylate ligands (L1-L4) in very good to excellent yield (75-92 %). The existence of 2-((2-methoxybenzylidene)amino) benzoic acid (L1) has been unambiguously demonstrated using NMR spectroscopy, MS and single-crystal X-ray diffraction. A neutral Pd-iminocarboxylate complex [{N O}PdMe(L1)] (N O=kappa(2)-N,O-ArCHNC6H4CO2 with Ar=2-MeOC6H4) C1 was prepared by treating stoichiometric amount of L1.Na with palladium precursor. The identity of C1 was confirmed by 1-2D NMR spectroscopy and single-crystal X-ray diffraction studies. Along the same lines, palladium complexes C2-C4 were prepared from ligands L2-L4 respectively. In-situ high-pressure NMR investigations revealed that these Pd complexes are amenable to ethylene insertion and undergo facile beta-H elimination to produce propylene. These palladium complexes were then evaluated in ethylene polymerization reaction and various reaction parameters were screened. When C1-C4 were exposed to ethylene pressures of 10-50 bar, formation of low-molecular-weight polyethylene was observed. |
DOI | 10.1002/asia.201901501, Early Access Date = JAN 2020 |
Type of Journal (Indian or Foreign) | Foreign |
Impact Factor (IF) | 4.056 |
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