Cationic metallocene/borate catalysts, generated from
zirconocene dimethyl compounds,
L
n
ZrMe2, and anilinium borate,
[HNMe2Ph]+[B(C6F5)4]-,
were used to polymerize 5-amino-1-pentenes
and one 4-amino-1-butene with dimethyl, diethyl, diisopropyl, or
diphenyl substitution patterns on
nitrogen. The monomer
5-(N,N-diisopropylamino)-1-pentene showed the
highest activity with
Cp*2ZrMe2/borate and was used for all further investigations. The catalytic
system Cp*2ZrMe2/borate was 4
times
more active than the corresponding methylaluminoxane-based system and
180 times more active than
the heterogeneous system,
TiCl3/Al(i-Bu)3. 1-Hexene
and 5-(N,N-diisopropylamino)-1-pentene
were
polymerized with Cp*2ZrMe2 and
rac-ethylenebis(tetrahydroindenyl) zirconium dimethyl,
rac-EB(THI)ZrMe2. Polymerization of both monomers with
Cp*2ZrMe2 displayed similar activities.
Hexene polymerizations with rac-EB(THI)ZrMe2 were
30 times more active than those with aminopentene.
5-(N,N-Diisopropylamino)-1-pentene polymerizations gave rise to isotactic
poly(aminopentene) with C
2
symmetric
catalysts, syndiotactic polymer with a C
s
symmetric catalyst, and atactic polymer with achiral
catalyst
precursors.
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