Rotational spectrum of the excited vibrational states of DCOOH and assignment of optically pumped laser transitions

The rotational spectrum of DCOOH in the 175-335 GHz region was investigated. Analysis of the spectrum made it possible to assign several dozen transitions in the nu(6), nu(8), and nu(5), vibrational states and to determine the rotational and centrifugal distortion constants. The derived parameters of the nu(6) state allowed four optically pumped laser transitions to be assigned. In addition, the ground state parameters for DCOOH and (DCOOH)-C-13 have been improved and for the first time those for (DCOOH)-O-18 and DCO (OH)-O-18 have been obtained. (C) 1996 Academic Press, Inc.