Electronic spectroscopy of N- and C-substituted chlorocarbazoles in homogeneous media and in solid matrix

Electronic spectra (absorption, fluorescence and phosphorescence emission spectra) of chlorocarbazoles 1a–e, 2a–b, 3a, 4a–b, 5a, 6a, 7a, 8a–c, 9a and 9b in acetonitrile and in solid matrix have been recorded at 298 and 77 K. The dynamic properties of the lowest excited singlet and triplet states in term of fluorescence and phosphorescence lifetime, τf and τp, fluorescence and phosphorescence quantum yield, φf and φp have been measured in the same experimental conditions and from these data the radiative and the radiationless rate constants (kf0, kisc, kf0(77), kisc(77), kp0 and knr0) and the intersystem crossing quantum yield, φisc, were derived.