15min:

T. HIRAO, Institute for Astrophysics and Planetary Sciences, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan.; H. OZEKI, Japan Aerospace Exploration Agency (JAXA), SMILES Mission Team, Tsukuba Space Center, 2-1-1 Sengen, Tsukuba 305-8505 Japan.; S. YAMAMOTO, Department of Physics and Research Center for the Early Universe, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.

Cyanohydrocarbons are molecules of great importance in cold dark clouds such as TMC-1. Due to such interests, CH₂CN has been studied by experimental and theoretical means, and these extensive investigations lead unambiguous identification of the molecule in interstellar matter\footnote W.~M.~Irvine et~al. Astrophys.~J. , 334, L107 (1988). . It turns out that an isomer CH₂NC was rarely studied experimentally, probably because of unstableness of this species compared with CH₂CN.

We recently recorded Fourier transform microwave (FTMW) spectra of CH₂NC at the University of Tokyo. About 0.3 1 percent of CH₃NC, synthesized by an ordinary way, was diluted in the Ar or Ne buffer gas at the pressure of 1 atm. The mixed gas was injected into the Fabry-P\acuteerot cavity via a pulsed nozzle, whose opening was synchronized with high voltage dc pulse to discharge to generate the aimed species. N=1₁₀-0₀₀ ( 22.2 GHz), 2₀₂-1₀₁, 2₁₂-1₁₁, and 2₁₁-1₁₀ ( 44.4 GHz) were recorded with well resolved fine and hyperfine structure. The molecular structure as well as a possibility of detection of this molecule will be discussed.