THE MICROWAVE SPECTRUM OF AMINO ACETONITRILE

Abstract

The microwave spectrum of amino acetonitrile, in the region 26.5-40 GHz, is dominated by two sets of prolate a-type R branch lines and a b-type Q branch series. Only one rotameric species is found and no exceptionally low-energy vibrational satellites are seen. When $D_{2}O$ is present in the waveguide, the $ND_{2}$ species and one NHD species are observed. The changes in rotational constant upon deuteration suggest that the most stable species is the form with a plane of symmetry in which the amino protons are directed toward the cyano group. This evidence and the lack of low vibrational states and other rotamers suggest that the molecule is locked in the stable form by dipole-dipole forces.