Optically Active Vinyl Polymers Containing Fluorescent Groups. 8. Synthesis and Properties of Copolymers of N-Vinylcarbazole and (-)-Menthyl Acrylate and (-)-Menthyl Methacrylate

Abstract

N-Vinylcarbazole was free radically copolymerized with (-)-menthyl acrylate and (-)-menthyl methacrylate in benzene at 55 "C to give optically active copolymers characterized by a marked induced optical rotation in the heteroaromatic co-units. Electronic absorption and emission properties, and the estimated reactivity ratios, are entirely consistent with quasi-random copolymerizations with, however, a tendency to\nalternation, especially for the N-vinylcarbazole unit. In contrast to the known behavior of copolymers of chiral\nmonomers with other vinylaromatic monomers, the differential dichroic absorption exhibits a maximum value\nfor copolymers containing approximately 40 mol % N-vinylcarbazole units. A similar maximum has been\nnoted previously for copolymers of N-vinylcarbazole with (-)-menthyl vinyl ether and confirms the unique value of carbazole units as probes for asymmetric induction in polymer chains.