Solvent-dependent Photoisomerization Quantum Yield of 2-Phenylazo-l-alkyl-3-methylimidazolium Cations in Ionic Liquids under S1(n, π*) Excitation

摘要

Photoisomerization quantum yields (Φ_(e-z)) of phenylazo-substituted imidazolium cations, which are counterparts of recently developed photochromic ionic liquids, were measured under S1(n, π*) excitation. The Φ_(e-z) values are lower in imidazolium-type ionic liquids than those in conventional solvents and in tert-alkylammonium-type ionic liquids. This observation was argued based on solute-solvent complex formation at imidazolium rings.