The ν1 band system of HNC

The [H,C,N] molecular system is a very important model system to many fields of chemical physics. The experimental characterization of highly excited vibrational states of this molecular system with a stable HCN and a metastable HNC isomer is of special interest. The emission spectrum of the HNC isomer has been recorded at 1463 K using hot gas molecular emission (HOTGAME) spectroscopy in the wavenumber region of 3400-3800cm-1 with a resolution of 0.01cm-1. The dense emission spectrum was analyzed with the spectrum analysis software SyMath™ implemented in the Mathematica™ computer algebra system. This work reports the analysis of the 1v2l0→0v2l0 band series up to v2=7 and of the 1v2l1→0v2l1 band series up to v2=4. 15 rovibronic substates of HNC including all l=1,3,5,7 sublevels of the v1v2lv3=17l0 highly excited bending combination mode have been characterized for the first time and for the 14 known vibrational sublevels it was possible to improve the existing spectroscopic constants substantially. 23 vibrational sublevels are located for the first time relative to the 0000 state. The exact position of these vibrational levels is an important contribution of this work to the spectroscopic characterization of the bending states of the [H,C,N] molecular system around the HNC minimum of the potential surface.