Femtosecond time-resolved UV-visible absorption spectroscopy of trans-azobenzene: dependence on excitation wavelength

Lednev, IK and Ye, TQ and Matousek, P and Towrie, M and Foggi, P and Neuwahl, FVR and Umapathy, S and Hester, RE and Moore, JN (1998) Femtosecond time-resolved UV-visible absorption spectroscopy of trans-azobenzene: dependence on excitation wavelength. In: Chemical Physics Letters, 290 (1-3). pp. 68-74.

PDF Femtosecond_time-resolved_UV-.pdf - Published Version Restricted to Registered users only Download (168kB) | Request a copy

Abstract

Femtosecond time-resolved UV-visible absorption spectroscopy has been used to study the photochemistry of trans-azobenzene in n-hexane. Excitation to the S-1(n pi*) state results in transient absorption bands at ca. 400 nm (strong) and 550 nm (weaker) which decay with a lifetime 2.5 +/- 0.2 ps on excitation at 503 nm, close to the S-1 origin, and with an additional fast component of ca. 0.6 ps on excitation at 390 or 420 nm, both well above the S-1 origin. Excitation to the S-2(pi pi*) state results in transient absorption at 400 nm which decays with a dominant component of ca. 0.9 ps and a weaker component of ca. 15 ps; this 400 nm band itself is observed to rise synchronously as a transient band at 475 nm decays with a lifetime of < 200 fs. These results are discussed in terms of the dual mechanism proposed for azobenzene photoisomerization.

Item Type:	Journal Article
Publication:	Chemical Physics Letters
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	20 Jul 2009 12:54
Last Modified:	19 Sep 2010 05:24
URI:	http://eprints.iisc.ac.in/id/eprint/18651

Actions (login required)

View Item