π ‐Stacked Polymers Bearing Side‐Chain Triphenylamine Moiety Composed of Vinyl Ketone and Methyl Methacrylate Units

Isopropenyl 4‐[bis(4‐methylphenyl)amino]phenyl ketone (IMAPK) (1‐[4‐(di‐ p ‐tolylamino)phenyl)‐2‐methylprop‐2‐en‐1‐one], a vinyl ketone monomer bearing a triphenylamine moiety in the side chain, was copolymerized with methyl methacrylate (MMA) by a free radical method. While the vinyl ketone is known to show rather low reactivity in radical polymerization, the copolymerization reactions afforded polymers at higher monomer conversions. Photophysical and electrochemical properties of the copolymers were compared with those of t ‐butyl 4‐[bis(4‐methylphenyl)amino]phenyl ketone (BMAPK) (1‐[bis(4‐methylphenyl)amino]phenyl‐2,2‐dimethylpropan‐1‐one) as a model compound of IMAPK unit. The polymers and the model compound exhibit distinctive absorption and emission properties and oxidation potentials. Especially, the copolymer with a unit ratio of [IMAPK]/[MMA] = 1/7 showed as high as about 1.5 times higher emission efficiency than BMAPK.