Ultrafast laser spectroscopic studies on carotenoids in solution and on those bound to photosynthetic pigment-protein complexes.

Abstract

Carotenoid excited singlet states, in particular, are typically very short lived. Therefore, time-resolved absorption spectroscopy in the time regime from femtoseconds to sub-milliseconds are required to unravel and understand the complicated relaxation and excitation energy-transfer pathways of carotenoids in solution and in photosynthetic pigment-protein complexes. The focus of this chapter is to explain how to use ultrafast time-resolved absorption spectroscopy in carotenoid research. The importance of a systematic approach to understanding the various carotenoid excited states by using a series of carotenoids with different conjugation lengths and the isomers of carotenoids is also emphasized.