Subpicosecond dynamics in the excited state absorption of all-trans-b-Carotene
نویسندگان
چکیده
We have investigated the time evolution of the transient absorption spectrum of all-trans-b-carotene in a number of solvents. In all cases we observe a loss of red and a gain of blue S1 ð2A g Þ ! SN excited state absorption on a 0.3–0.4 ps time scale. To explain these observations, a model is proposed in which distorted molecules formed in S2 ð1Bu Þ relax back to the all-trans state in S1 ð2A g Þ. 2002 Published by Elsevier Science B.V. Abbreviations: Car – carotenoid; ESA – excited state absorption; IC – internal conversion; SE – stimulated emission; Chl – chlorophyll; SADS – species associated difference spectrum; fwhm – full width at half maximum
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