Organized carotenoid films: excited states and dual emissions

Abstract

The absorption, emission and excitation spectra of crocetin dialdehyde (CDA) were obtained in solution and in Langmuir-Blodgett (LB) films. Dual fluorescence was observed in both cases and, for the first time, in an organized molecular layer of a carotenoid. Comparison of the emission and absorption spectra in solution and LB films suggests the formation of aggregates in LB films. The observation of dual emission and the shift in the excited states in carotenoid LB films are discussed with particular relevance to the possible self-organization in photosynthetic light-harvesting antennae.