Infrared diode laser spectroscopy of the trimers Rg2N2O (Rg = Ne, Ar, and Kr): The ν1 symmetric stretch region of N2O

► The rovibrational spectra of the van der Waals trimers Ne2N2O and Ar2N2O are studied in the ν1 region of N2O-monomer. ► The Q-branch of Kr2N2O is tentatively assigned. ► The band-origins in RgnN2O shift approximately linearly for n = 0, 1 and 2 from that of the ν1 band of N2O-monomer. ► The incremental shifts for Rg2N2O can be explained by the model based on a Buckingham intermolecular potential.