Laser-induced optoacoustic studies of the non-radiative deactivation of ICT probes DMABN and DMABA

Laser induced optoacoustic spectroscopy has been used to determine the relative contribution of the intersystem crossing and internal conversion to the non-radiative energy dissipation from the two excited ICT probes p-N,N-dimethylaminobenzonitrile (DMABN), and p-N,N-dimethylaminobenzaldehyde (DMABA) in solvents of different polarity. It is observed that while intersystem crossing is the main non-radiative deactivation process for DMABN in all the solvents studied this is not the case in polar solvents for DMABA.