High-resolution infrared study of trans-monodeutero-diimide, HNND

Infrared spectra of trans-monodeutero-diimide, HNND, have been recorded between 760 and 3250 cm(-1) at a resolution of ca. 0.005-0.007 cm(-1), from which the fundamental bands nu(1), nu(4), nu(5), and nu(6) of this isotope have been studied. A detailed analysis of the a, b-Coriolis interacting band system nu(5), nu(6) near 1100 cm(-1) is presented. The nu(4) band at 1475 cm(-1) has been analyzed by a model including c-Coriolis and Delta K-a = +/-2 vibrational resonance with the close lying nu(3) band at 1538 cm(-1). Only 18 transitions in nu(3) which obtain their intensity through interaction with the nu(4) band have been assigned. Together with the observed perturbation effects in nu(4) they provide valuable information for the nu(3) level, too. In the nu(1) band around 3110 cm(-1) numerous local crossings due to vibrational and c-Coriolis interactions with the unobserved binary combinations 2 nu(3), nu(3) + nu(4), and 2 nu(4) have been identified. The present analyses yield a number of spectroscopic constants for the nu(1), nu(3), nu(4), nu(5), and nu(6) levels and various interaction constants. From a simultaneous ground state combination difference analysis of the four observed bands the following ground state rotational constants are obtained: A(0) = 7.384213(4) cm(-1), B-0 = 1.1959457(6) cm(-1), and C-0 = 1.0255827(6) cm(-1). (C) 1997 Academic Press, Inc.