Ultrafast Excited State Dynamics of trans‐4‐Aminoazobenzene Studied by Femtosecond Transient Absorption Spectroscopy

Autor:	Bing Zhang, Song Zhang, Kai Liu, Ya-ping Wang, Si-mei Sun
Rok vydání:	2013
Předmět:	Intersystem crossing Photoisomerization Chemistry Excited state Femtosecond Ultrafast laser spectroscopy Potential energy surface Physical and Theoretical Chemistry Atomic physics Internal conversion (chemistry) Photochemistry Spectroscopy
Zdroj:	Chinese Journal of Chemical Physics. 26:651-655
ISSN:	2327-2244 1674-0068
Popis:	The ultrafast excited state dynamics of trans‐4‐aminoazobenzene (trans‐4‐AAB) in ethanol was investigated by femtosecond transient absorption spectroscopy. After being excited to the S2 state by 400 nm, trans‐4‐AAB decays from the S2 state to the hot S1 state by internal conversion with time constant of ∼70 fs. The photoisomerization through inversion mechanism on the S1 potential energy surface and the internal conversion from the S1 state to the hot S0 state are observed, respectively. The average timescale of these two decay pathways is ∼0.7 ps. And the vibrational cooling of the hot S0 state of cis‐ and trans‐4‐AAB occur with time constants of ∼4 and ∼13 ps, respectively. Furthermore, the ultrafast intersystem crossing process are also observed. The timescale of intersystem crossing from the S2 state to the T4 state is about 480 ps while from the S1 state to the T2 state is ∼180 ps.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::50341b9664cdc34a04e7bd3ca3491209 https://doi.org/10.1063/1674-0068/26/06/651-655 Zobrazit plný text záznamu