Synthesis and optical properties of poly(N-octyl-m-benzamide)s bearing an oligothiophene chromophore on the benzene ring

The precise arrangement of π-conjugated molecules is of significant importance for applications in optoelectronic devices. We have previously demonstrated the potential utility of poly(N-alkyl-p-benzamide)s as a scaffold for this purpose. In this paper, we report a controlled chain-growth polymerization of methyl 3-octylaminobenzoate having a bithiophene chromophore at the 5-position of the benzene ring with improved polymerization activity, which gives poly(N-octyl-m-benzamide)s with better solubility. The introduction of a terthiophene chromophore at the propagating end is also described. From the spectroscopic data and theoretical investigations, it was found that neighboring bithiophene chromophores have π–π interactions, and the excited energy can migrate along the polymer chain.