Supersonic jet spectroscopy of N-(4-cyanophenyl)carbazole and its complexes
Abstract
The laser-induced fluorescence spectra of jet-cooled N-(4-cyanophenyl)carbazole (CPC) and its (1 : 1) complexes with various partner species Ar, C6H6, C6H12, CH3OH, CHCI3, CH3CN are presented. With CCI4, no fluorescent complex was observed. The other 1 : 1 complexes observed gave rise to red-shifted features, which indicates a stabilisation of the S1 state of the complex relative to its ground state. Inductive and dispersive forces thus play an important role in both non-polar and solvents with small dipole moment and large polarisability. The dipole–dipole interactions involve the dipoles of the polar solvent and CPC in an anti-parallel arrangement. With the exception of CPC–Ar2, no complexes of higher than 1 : 1 stoichiometry were observed. An attempt was made to produce in the jet the characteristic red-shifted broad emission from the so-called twisted intramolecular charge transfer (TICT) states seen in polar solution. No such emission was observed.