The submillimeter-wave spectrum of the chloromethyl radical, CH2Cl, in the ground vibronic state

We have extended the measurement of submillimeter wave transitions of CH2Cl between 418 and 470 GHz for the two isotopic species of Cl. The radical was produced in a fast flow system by hydrogen abstraction of CH3Cl by Cl atoms obtained from a 2450 MHz microwave discharge in Cl2 diluted with helium. A global least-squares analysis including the previous and the newly observed transitions led to a more precise set of rotational, fine and hyperfine constants for the two isotopomers in their ground vibronic state. In addition, we have also observed CH2Cl by the 248 nm photolysis of CH2BrCl, leading to a single 1/e lifetime of 146 ms.