Precise One-Pot Synthesis of End-Functionalized Conjugated Multi-Block Copolymers via Combined Olefin Metathesis and Wittig-type Coupling

A precise, one-pot synthesis of end-functionalized block copolymers consisting of poly(9,9-di-n-octylfluorene-2,7-vinylene)s (PFVs) and oligo(2,5-dialkoxy-1,4-phenyl-enevinylene) or terthiophene units as the middle segment have been prepared by olefin metathesis of the vinyl group in the PFV chain ends followed by subsequent Wittig-type coupling. Formation of the block copolymers and the quantitative efficiency in the end-functionalization can be confirmed by synthesis of amphiphilic block copolymers containing poly(ethylene glycol) at the both polymer chain ends. Effect of PFV conjugation length, middle segment, and the end groups toward the emission properties have been studied: the polymers containing ferrocene moiety at the chain ends displayed unique emission/quenching properties.