Chemical Physics Letters, Vol.683, 448-453, 2017
Spectroscopic properties of the S-1 state of linear carotenoids after excess energy excitation
Properties of the S-1 state of neurosporene, spheroidene and lycopene were studied after excess energy excitation in the S-2 state. Excitation of carotenoids into higher vibronic levels of the S-2 state generates excess vibrational energy in the S-1 state. The vibrationally hot S-1 state relaxes faster when carotenoid is excited into the S-2 state with excess energy, but the S-1 lifetime remains constant regardless of which vibronic level of the S-2 state is excited. The S+ signal depends on excitation energy only for spheroidene, which is likely due to asymmetry of the molecule, facilitating conformations responsible for the S* signal. (C) 2017 Elsevier B.V. All rights reserved.