RADIATIVE LIFETIMES OF THE CN (A2-PI-I) ELECTRONIC STATE

Radiative lifetimes have been measured for CN (A2-PI(i) v' = 2 ... 7). Ground-state radicals formed in the 193 nm photolysis of C2N2 and ClCN were excited to A2-PI(i) v' = 2 ... 7) vibrational levels. The decay was monitored by following the fluorescence . Cascading effects were eliminated by working at low pressures and monitoring emission from a single vibrational band. Quenching rates and zero-pressure radiative lifetimes were obtained from Stem-Volmer plots. The lifetimes are significantly lower than previous measurements and theoretical calculations for vibrational states v' > 2