Networks of anharmonic resonance systems in the rovibrational overtone spectra of the quasilinear molecule HCNO

Abstract

AbstractThe infrared spectrum of fulminic acid, HCNO, has been measured in the range 700‐7000 cm−1 with a Bruker IFS 120 HR interferometer. More than 130 new vibrational levels have been identified. Power series coefficients of these levels are given. Each vibrational level with its rotational levels is locally or globally perturbed. It was possible to classify most of the interactions into a grand network of Coriolis‐ and/or Fermi‐type resonance systems by using the previously known basic resonance systems 00010/00002 and 00100/00004. In addition, a new basic resonance for HCNO could be identified in the system 00015/01000/00103. As a consequence of the many interactions many so called “resonance‐enhanced” rovibrational subbands have been assigned. The identification and partial analysis of the resonance systems have been carried out, first with the help of different presentations of reduced term values and second by determining the J‐value separation between e and f crossing points. In this paper, the resonance systems 01100/01004/00203/00115 and 00014/00110/00102, which are combinations of the above mentioned basic resonance systems, will be discussed. Some further resonance systems that can be deduced from these are discussed in detail, too.