THE MICROWAVE SPECTROSCOPY OF AMINOACETONITRILE IN THE VIBRATIONAL EXCITED STATE

Abstract

Aminoacetonitrile (NH$_2$CH$_2$CN) is a potential precursor of the simplest amino acid, glycine and was detected toward SgrB2(N). $footnote{A. Belloche, K. M. Menten, C. Comito, H. S. P. M\"{u}ller, P. Schilke, J. Ott, S. Thorwirth, and C. Hieret, 2008, textit{Astronom. & Astrophys.} underline{textbf{482}}, 179 (2008).}$ It is expected that the strongest transitions will be found in the terahertz region so that we have extended measurements up to 1.3 THz. $footnote{Y. Motoki, Y. Tsunoda, H. Ozeki, and K. Kobayashi, textit{Astrophys. J. Suppl. Ser.} underline{textbf{209}}, 23 (2013).}$ This study gave an accurate prediction of aminoacetonitrile up to 2 THz which is useful for astronomically search. This molecule has a few low-lying vibrational excited states and the pure rotational transitions in these vibrational excited states are expected to found. $footnote{B. Bak, E. L. Hansen, F. M. Nicolaisen, and O. F. Nielsen, textit{Can. J. Phys.} underline{textbf{53}}, 2183 (1975).}$ We found a series of transitions with intensity of about 30$%$. Eighty-eight spectral lines including both {it a}-type and {it b}-type transitions were recorded in the frequency region of 400 - 450 GHz, and centrifugal distortion constants up to the sextic term were determined. Perturbation was recognized. We will report the current status of the analysis.