THE ROTATIONAL AND ROTATION-BENDING SPECTRUM OF (HCNO)-N-15 - AN EXTENDED ANALYSIS OF THE SPECTRAL REGIONS 18-40-GHZ, 90-440-GHZ AND 170-1300-CM(-1)

The rotational spectrum of the N-15-substituted quasilinear molecule f ulminic acid, HCNO, has been measured in the frequency range from 90 t o 440 GHz covering relational transitions up to J = 19<--18. Relationa l transitions arising from (HCNO)-N-15 molecules in 52 vibrational lev els were detected and assigned. Additional information was obtained by measuring the direct l-type transitions far nu(5) = 1 and 3 and for n u(4) = 1 in the frequency range from 18 to 40 GHz. With the informatio n from the relational spectrum the analysis of the far and mid-infrare d spectra (170-1300 cm(-1)), which was started by Wagner et al. [J. Mo l. Spectrosc. 162, 82 (1993)], could be extended so that the vibration al term values of (HCNO)-N-15 were determined for almost every state b elow 2500 cm(-1). The assignment of the 114 subbands involved allowed in turn the assignment of 25 subbands in the mid-infrared from the dat a of Quapp et al. [J. Mol. Spectrosc. 160, 540 (1993)]. The infrared s pectra were recorded with a Bruker IFS 120 KR interferometer at resolu tions between 0.0019 and 0.0034 cm(-1). For the vibrational states (nu (1) nu(2) nu(3) nu(4) nu(5)) = (00000), (00001), (00002), (00003), (00 004), (00010), (00011) an (00100) the spectroscopic constants of an ef fective Hamiltonian for linear molecules could be improved by combinin g the already published infrared data with the millimeter wave, microw ave and newly assigned infrared data presented in this work. For the s tates (00013) and (00101) these constants were also calculated. A cali bration problem with the infrared data became obvious and important. T he effects of a Fermi-type resonance between the vibrational levels (0 0004)(Oe) and (00100)(Oe) and a Coriolis resonance between the slates (00002) and (00010) on the rotational and rovibrational spectra were o bserved and analysed. The difficulties encountered in determining the Coriolis resonance parameters are discussed.