= Solution
\b[Syndiotactic <polypropylene>] is the expected principal product:
$$
\boxed{[\mathrm{-CH_2-CH(CH_3)-}]_n,\qquad\text{alternating configurations at successive substituted carbons}.}
$$
The bridged cyclopentadienyl–fluorenyl <metallocene> has approximately $C_s$ site <symmetry>. Activation by <methylaluminoxane> gives a cationic zirconium–alkyl <polymerization-active site>. Repeated <coordination chemistry> and <migratory insertion> of <propene> extend the chain. The two environments encountered during successive insertions favor alternating <stereochemistry>, giving syndiotactic <tacticity>. There is no stoichiometric small <molecule> eliminated in the propagation step; initiator fragments and chain-transfer products belong to the end groups.
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