Excited state dynamics of N-(4-azaindan-1,3-dion-2-yl)pyridinium betaine in solutions

The excited state dynamics of N-(4-azaindan-1,3-dion-2-yl)pyridinium betaine (4N-IPB) in various solvents were studied using steady state absorption, fluorescence, and transient absorption measurements. The 4N-IPB molecules in solutions show weak fluorescence and possess a very large Stokes-shift of the fluorescence band even in non-polar solvents with low dielectric constants. The relaxation rate of 4N-IPB in alcohols faintly depends on the solvent viscosity. The excited state relaxation mechanism involving two excited states is similar to that of the IPB molecule, however the excited state relaxation of 4N-IPB is slightly faster.