Chemical control of Hemithioindigo-photoisomerization – Substituent-effects on different molecular parts

Chemical Physics Letters, 2008, 455, 197–201 published on 02.03.2008
Chemical Physics Letters, online article

Hemithioindigo-molecules show a photochromic behavior due to a photo-induced Z/E-isomerization on a picosecond timescale. Changes in the reaction kinetics, caused by polar substituents attached to the thioindigo-moiety, are studied using time-resolved absorption spectroscopy. The experiments reveal that substituents in the thioindigo-part influence the reaction dynamics in a different manner as previously found for stilbene-substitution. The results are discussed in the context of inductive- and resonanceeffects and lead to an improved understanding of the molecular mechanisms of the Hemithioindigophotoreaction.

TU München