Determination of the equilibrium structure of protonated nitrogen by high resolution infrared laser spectroscopy

Abstract

We report the measurement of new high‐J transitions (up to J=41) in the fundamental N–H stretch band and of the 1110–0110 bending hot band by velocity modulation infrared laserspectroscopy. These data were combined with measurements of the 100, 0110, and 001 fundamentals of both HNN+ and DNN+, and of the 1110–0110 hot band of DNN+, and of microwave ground state rotational transitions, made by several groups, in a simultaneous weighted least‐squares analysis; from this analysis, the equilibrium structure of protonated nitrogen was determined to be: r NH =1.033 59(43) Å, r NN =1.092 766(92) Å. Several vibration–rotation and anharmonicity constants were determined; comparisons with high level a b i n i t i o calculations are presented.