Influence of polymer conformations on the aggregation behaviour of alternating dialkylsilylene-[4,4′-divinyl(cyanostilbene)] copolymers

Abstract

The influence of the substituents at silicon on the aggregation enhanced emission (AEE) of alternating dialkylsilylene-[4,4′-divinyl(cyanostilbene)] copolymers 3 and 4 is examined. The presence of the bulky isopropyl group in 3b significantly enhances the quantum yield upon aggregation. On the other hand, the emission intensity of the methyl-substituted polymer 3a is only slightly enhanced under the same conditions. The bulky isopropyl substituents on silicon may exert the Thorpe–Ingold effect on these copolymers resulting in conformation difference, which may dictate the nature of the aggregation between polymers, and hence, the photophysical behaviour of these polymers.