Fluorescence decay of aromatic vapours. IV. Lifetime measurements on three further azabenzenes

Abstract

Lifetime studies of the three azabenzenes s-triazine, pyridazine and pyrazine are reported. They show quite different behaviour. Lifetimes of four single vibronic levels of s-triazine were measured and show that an additional decay channel is operating. The fluorescence from pyridazine is so fast that it was indistinguishable from the exciting lamp pulse. Lifetimes of six single vibronic levels of pyrazine were measured and were shown to be pressure-dependent. These results fit quite well into the current understanding of the behaviour of the azabenzenes.