Spectroscopic and theoretical characterisation of the ν2 band of Ar⋯DN2+

The rotationally resolved infrared spectrum of the ν2 stretching vibration of Ar⋯DN2+ has been observed by means of tunable diode laser absorption spectroscopy through a supersonic planar plasma. Its band origin is found at 1593.6058(2) cm−1, and a large transition moment of 0.54 D is predicted from CCSD(T) calculations. An accurate mixed experimental/theoretical equilibrium structure is established, yielding RAr⋯H(e)=1.8854 Å, RH⋯N(e)=1.0752 Å and R(e)NN=1.0929 Å.