Identification of the interstellar cyanomethyl radical (CH2CN) in the molecular clouds TMC-1 and Sagittarius B2

The astronomical identification of the cyanomethyl radical, CH2CN, in interstellar clouds is reported. The complex fine and hyperfine structures of the lowest rotational transitions at about 20.12 and 40.24 GHz are resolved in TMC-1. The abundance of CH2CN relative to that of H2 in TMC-1 is estimated at 5 X 10 to the -9th. In Sgr B2, the hyperfine structure is blended in the higher frequency transitions at 40, 80, and 100 GHz, although the spin-rotation doubling is clearly evident.