Photophysical models of aromatic polyesters: excited state interactions in bis(phenalkyl)terephthalate

Summary

The nature of the excited state interactions in poly(ethylene terephthalate) is still subject to debate. We study a new series of model compounds composed of a central terephthaloyl group condensed with α-hydroxy-ω-phenyl-n-alkanes. Although the molecular architecture prevents these molecules from achieving symmetric ring-ring overlap, the steady-state fluorescence spectra are remarkably similar to those of other models studied earlier, where such overlap was expected. The solvent polarity dependence suggests that the excited state complex is an exciplex and not an excimer.