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Vanadium(III) complexes containing phenoxy–imine–thiophene ligands: Synthesis, characterization and application to homo‐ and copolymerization of ethylene
Author(s) -
Prado Nayara T.,
Ribeiro Ronny R.,
L. Casagrande Osvaldo
Publication year - 2017
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.3678
Subject(s) - chemistry , vanadium , methylaluminoxane , ethylene , polymer chemistry , thiophene , monomer , polymerization , imine , catalysis , polyethylene , copolymer , organic chemistry , polymer , metallocene
A set of vanadium(III) complexes, namely {SNO}VCl 2 (THF) 2 ( 2a , SNO = thiophene‐(N═CH)‐phenol; 2b , SNO = 5‐phenylthiophene‐(N═CH)‐phenol; 2c , SNO = 5‐phenylthiophene‐(N═CH)‐4‐ tert ‐butylphenol; 2d , SNO = 5‐methylthiophene‐(N═CH)‐phenol; 2e , SNO = 5‐methylthiophene‐(N═CH)‐4‐ tert ‐butylphenol; 2f , SNO = 5‐methylthiophene‐(N═CH)‐2‐methylphenol; 2g , SNO = 5‐methylthiophene‐(N═CH)‐4‐fluorophenol), were synthesized by reaction of VCl 3 (THF) 3 with phenoxy–imine–thiophene proligands ( 1a – g ). All vanadium(III) complexes were characterized using elemental analysis and infrared and electron paramagnetic resonance spectroscopies. Upon activation with methylaluminoxane (MAO), vanadium precatalysts 2a – g proved active in the polymerization of ethylene (213.6–887.2 kg polyethylene (mol[V]) −1 ⋅h −1 ), yielding high‐density polyethylenes with melting temperatures in the range 133–136 °C and crystallinities varying from 28 to 41%. The 2e/ MAO catalyst system was able to copolymerize ethylene with 1‐hexene affording poly(ethylene‐ co ‐1‐hexene)s with melting temperatures varying from 126 to 102 °C and co‐monomer incorporation in the range 3.60–4.00%.