Nonradiative Deactivation of Excited Hemicyanines Studied with Submolecular Spatial Resolution by Time-Resolved Surface Second Harmonic Generation at Liquid-Liquid Interfaces

作者：Martin Gassin Gaelle; Villamaina Diego; Vauthey Eric^*

来源：Journal of the American Chemical Society, 2011, 133(8): 2358-2361.

DOI：10.1021/ja109813j

The excited-state dynamics of aminostilbazolium dyes is known to be dominated by nonradiative deactivation through large-amplitude motion. In order to identify the coordinate(s) responsible for this process, the excited-state lifetimes of two dialkylaminostyryl-methylpyridinium iodides have been measured at liquid-liquid interfaces using time-resolved surface second harmonic generation. We found that the decay time of the excited-states of both compounds was increasing with the viscosity of the apolar phase, consisting of n-alkanes of varying length, but was unaffected by that of the polar phase, made of water/glycerol mixtures. This indicates that the nonradiative deactivation is associated with the twist of the dialkylaniline group, which is located in the apolar part of the molecule.

• 出版日期2011-3-2