First vibrational investigations of N2O-H2O, N2O-(H2O)2, and (N2O)2-H2O complexes from the far to the near-infrared spectral region by neon matrix isolation and ab initio calculations.

We present for the first time the investigation of water molecules complexed with dinitrogen monoxide, two abundant molecules in atmosphere, in solid neon using Fourier transform infrared (IR) spectroscopy. We identify at least three complexes from concentration effects, N2O-H2O, N2O-(H2O)2, and (N2O)2-H2O, by observation of new absorption bands close to the monomer fundamental modes from the far to the near IR region. We highlight the presence of isomers for the N2O-H2O complex with the help of theoretical calculations at second order Møller-Plesset (MP2) and coupled-cluster single double triple-F12a/aug-cc-pVTZ levels. The observed frequencies for the N2O-(H2O)2 and (N2O)2-H2O complexes are compared with MP2/aug-cc-pVTZ harmonic data. Anharmonic coupling constants have been derived from the observations of overtones and combination bands.