Luminescence and circularly polarized luminescence of excited-state chiralstructures in one-dimensional PIC-J dye aggregates

Luminescence (TL) and circularly polarized luminescence (CPL) spectra of po lymeric pseudoisocyanine dye J-aggregates (PIC-J) are investigated to clari fy the molecular arrangements generating a one-dimensional excitonic J-band in the excited state. In the presence of L- and D-phenylalaninol (PAOL), t he PIC-J aggregates are found to reveal CPL spectra at room temperature wit h luminescence dissymmetry factors g(lum) for J-bands of - 0.05, which are comparable in magnitude with the corresponding Kuhn g-factors in the ground state derived by comparison of J-bands in circular dichroism and absorptio n spectra. Chiroptical and helical structures along with one-dimensional ch ains are considered to generate Pfeiffer effects through intermolecular int eractions between PIC-J dye and chiral PAOL. CPL and TL spectra of PIC-J dy es in the presence of DNA and phenylethylamine are further considered. (C) 2000 Elsevier Science B.V. All rights reserved.