The free jet cooled, laser induced fluorescence spectrum of s y m-triazine

Abstract

A laser induced fluorescence excitation spectrum has been obtained for sym‐triazine seeded in a free jet expansion in He. Under these conditions, the translational, rotational, and (probably) vibrational temperature of the sym‐triazine is found to be 1 °K. This low temperature yields a greatly simplified vibronic spectrum for the à ¹E^″↔X̃ ¹A^′₁ transition, with implications for vibrational assignments and the interpretation of the Jahn–Teller and pseudo‐Jahn–Teller effect in the à ¹E^″ state. Completely resolved R and P rotational structure has been observed for selected vibronic transitions. Lifetime and collisional quenching cross sections have also been obtained for selected vibronic levels of the à ¹E^″ state.