Disubstituted polyacetylenes containing photopolymerizable vinyl groups and polar ester functionality: Polymer synthesis, aggregation-enhanced emission, and fluorescent pattern formation

Diphenylacetylene monomers functionalized with vinyl and ester groups (1 and 2) were synthesized. The monomers were polymerized by WCl6-Ph4Sn into their corresponding polymers (P1 and P2) with the (meth)acrylic functionality remained intact, as verified by the structural analysis of the polymers using spectroscopic methods. The polymers are soluble in common organic solvents and form films of good quality when their solutions are spin-coated. The solutions of the polymers emit green light upon photoexcitation. Their emission spectra shift to longer wavelengths and narrow in widths when the solution concentrations are increased, presumably due to the formation of the intramolecular excimers. When the polymer chains are aggregated, their emission efficiencies are increased (Phi(F) up to similar to 88%), showing a unique phenomenon of aggregation-enhanced emission. The (meth)acrylic groups bestow photosensitivity on the polymers, whose photo-cross-linking enables ready fabrication of highly fluorescent photoresist patterns.