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Catalytic diversity of diene complexes of niobium and tantalum on polymerizations of ethylene, norbornene, and methyl methacrylate
Author(s) -
Mashima Kazushi
Publication year - 2000
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/1521-3900(200010)159:1<69::aid-masy69>3.0.co;2-y
Subject(s) - methylaluminoxane , tantalum , polymerization , norbornene , diene , polymer chemistry , metallocene , ethylene , niobium , metathesis , materials science , methyl methacrylate , chemistry , catalysis , organic chemistry , polymer , natural rubber
Half‐metallocene diene complexes of niobium and tantalum catalyzed three‐types of polymerization: (1) the living polymerization of ethylene by niobium and tantalum complexes, MCl 2 (η 4 ‐1,3‐diene)(η 5 ‐C 5 R 5 ) ( 1‐4 ; M = Nb, Ta; R = H, Me) combined with an excess of methylaluminoxane; (2) the stereoselective ring opening metathesis polymerization of norbornene by bis(benzyl) tantalum complexes, Ta(CH 2 Ph) 2 (η 4 ‐1,3‐butadiene)(η 5 ‐C 5 R 5 ) ( 11 : R = Me; 12 : R = H) and Ta(CH 2 Ph) 2 (η 4 ‐ o ‐xylylene)(η 5 ‐C 5 Me 5 ) ( 16 ); and (3) the polymerization of methyl methacrylate by butadiene‐diazabutadiene complexes of tantalum, Ta(η 2 ‐RN=CHCH=NR)(η 4 ‐1,3‐butadiene)(η 5 ‐C 5 Me 5 ) ( 25 : R = p ‐methoxyphenyl; 26 : R = cyclohexyl) in the presence of an aluminum compound ( 24 ) as an activator of the monomer.