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Stereospecific Polymerization of Isoprene with Nd(BH 4 ) 3 (THF) 3 /MgBu 2 as Catalyst
Author(s) -
Bonnet Fanny,
Visseaux Marc,
Pereira Angela,
Bouyer Frédéric,
BarbierBaudry Denise
Publication year - 2004
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200300289
Subject(s) - isoprene , stereospecificity , tetrahydrofuran , polymerization , catalysis , bimetallic strip , chemistry , neodymium , stoichiometry , polymer chemistry , polymer , copolymer , organic chemistry , solvent , optics , laser , physics
Summary: The neodymium trisborohydride Nd(BH 4 ) 3 (THF) 3 (THF = tetrahydrofuran) has been used as a catalyst precursor for isoprene polymerization for the first time. Associated to an excess of Al(Et) 3 , the resulting catalyst is moderately active, giving a mixture of cis ‐ and trans ‐ polymer. Addition of a stoichiometric amount of MgBu 2 to Nd(BH 4 ) 3 (THF) 3 affords a stereospecific catalyst providing trans ‐1,4‐polyisoprene, more than 96% regular. That dual component Nd/Mg system also shows a better efficiency and good control of the molecular weights. A molecular structure is tentatively attributed to a bimetallic active species, based on 1 H NMR experiments.Possible Nd/Al and Nd/Mg active initiating species.