Preparation and Properties of a Hydrolytically Stable Cyclooctyne-Containing Polymer

Published as part of the Cluster Synthesis of Materials

Abstract

A poly[(phenylene vinylene)-co-dibenzocyclooctyne] polymer prepared by Wittig polymerization chemistry between dibenzocyclooctyne bisaldehyde [DIBO-(CHO)₂] and bis(triethyleneglycol)phenylbis(tributylphosphonium) dibromide is reported. The resulting polymer exhibits moderate molecular weight (M_n: 10.5 kDa, M_w: 21.3 kDa, Ð: 2.02) and is fluorescent. It could be readily functionalized by strain-promoted alkyne-azide cycloadditon with different azides, and fluorescence of the polymer was preserved after functionalization. Grafting azide-terminated 5 kDa poly(ethylene glycol) monomethyl ether chains drastically affected the solubility of the polymer. Cross-linking the polymer with poly(ethylene glycol) that was terminated at both ends with azide groups gave access to a fluorescent organogel that could be dried and reswollen with water to form a hydrogel.

Key words

Wittig reaction - cycloaddition - cyclooctyne - conjugated polymer - polymer functionalization - cross-linking

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