title: Relaxation pathways of excited N-(triphenylmethyl)salicylidenimine in solutions.
abstract: Excited state relaxation of N-(triphenylmethyl)-salicylidenimine (MS1) in protic and aprotic solvents has been investigated by means of absorption pump-probe spectroscopy with femtosecond time resolution and fluorescence spectroscopy with picosecond time resolution. Short-lived excited states and long-lived photoproducts have been identified from the differential absorption spectra. Excited states and photoproducts were different under excitation of enol-closed and cis-keto tautomers. As a result, the commonly accepted excited state relaxation model of aromatic anils, which assumes an ultrafast transformation of excited enol-closed tautomers into cis-keto tautomers, has been modified. Performed quantum chemical calculations suggest that hydrogen-bonded ethanol molecules facilitate formation of cis-keto tautomers and are responsible for their different relaxation pathways in comparison with relaxation of excited enol-closed tauromers. Fluorescence decay on a nanosecond time scale was attributed to aggregated MS1 molecules.
authors.affiliation: Institute of Physics, Center for Physical Sciences and Technology, Savanoriu Ave 231, LT-02300 Vilnius, Lithuania. renata@ar.fi.lt
authors.forename: Renata
authors.initials: R
authors.lastname: Karpicz
authors.forename: Vidmantas
authors.initials: V
authors.lastname: Gulbinas
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Lewanowicz
authors.forename: Mindaugas
authors.initials: M
authors.lastname: Macernis
authors.forename: Juozas
authors.initials: J
authors.lastname: Sulskus
authors.forename: Leonas
authors.initials: L
authors.lastname: Valkunas