The rotational constants of acetylene-d

Abstract
The rotational spectrum of acetylene-d has been measured up to 418 GHz in its vibrational ground state and in its degenerate excited states v 4 = 1 and v 5 = 1. These data have been combined with the high resolution infrared measurements of the v 4 and v 5 bending vibrations to determine with high accuracy the rotational and centrifugal distortion constants.