Synthesis and optical properties of simple amine-containing conjugated polymers

Conjugated polymers (CPs) containing amino groups have been synthesized, and their optical properties in both solution and thin film have been studied. New monomers required for the synthesis of these polymers have been readily prepared via efficient synthetic routes. These monomers have been successfully polymerized with a variety of comonomers. The spectral positions of the absorption and emission spectra correlate with the degree of electron density on the polymer chain. Polymers containing N-alkylcarbazole units display similar optical properties in solution to most CPs. Polymers with dialkylamino groups, however, display very different optical properties, including broadened absorbance and emission spectra, larger Stokes shifts, and longer excited state lifetimes. These results are consistent with a significant difference between the molecular geometries of the absorbing and emitting states. The solid state emission of most of the polymers is sufficient to warrant them for consideration as fluorescent sensing materials.