Collisional Relaxation of NCN: An Experimental Study with Laser-Induced Fluorescence

Abstract

Abstract Collisional relaxation of NCN produced by photolysis of NCN3 at a wavelength of 248 nm has been investigated with laser-induced fluorescence (LIF) in a temperature range of 240–293 K and a pressure range of 10–800 mbar with different bath gases (He, Ne, Ar, Kr, H2, N2, O2, and N2O). LIF excitation spectra were recorded, and LIF intensity-time profiles experimentally obtained at an excitation wavelength of 329.01 nm have been fitted with biexponential functions. The pressure and bath gas dependence of the rate coefficients obtained was rationalized in terms of a simple Landau–Teller/Schwartz–Slawsky–Herzfeld model, and notable influences of vibrational energy transfer to the rate of the overall relaxation process have been found. Evidence was obtained for a two-channel vibrational relaxation in NCN.