Vibrational relaxation of HCl(v=1) by Cl atoms

The vibrational relaxation of HCl(v=1) by Cl atoms at 294°K has been carefully measured by two different techniques. A discharge-flow-tube, laser-fluorescence method yielded a deactivation rate constant kCl = (8.8±2.6) ×10−12 cm3 molecule−1⋅sec−1. A refinement of the uv laser photodissociation method gives a value of kCl = (8±3) ×10−12. The wide ranges of the argon third body pressure and of the HCl pressure show that the process is clearly bimolecular and not termolecular.