Pd-iminocarboxylate complexes and their behavior in ethylene polymerization

TitlePd-iminocarboxylate complexes and their behavior in ethylene polymerization
Publication TypeJournal Article
Year of Publication2020
AuthorsDeshmukh, SS, Gaikwad, SR, Gonnade, RG, Pandole, SP, Chikkali, SH
JournalChemistry-An Asian Journal
Volume15
Issue3
Pagination398-405
Date PublishedFEB
Type of ArticleArticle
ISSN1861-4728
Keywordsimine, 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.

DOI10.1002/asia.201901501, Early Access Date = JAN 2020
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

4.056

Divison category: 
Center for Material Characterization (CMC)
Central NMR Facility
Polymer Science & Engineering

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