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

The precise arrangement of pi-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 pi-pi interactions, and the excited energy can migrate along the polymer chain.