The mid-infrared spectra of liquid phase argon/nitrogen (80-121 K), krypton/nitrogen (78-121 K) and xenon/nitrogen (80-123 K) mixtures are reported. Superposed on the broad, collision-induced N2 band, for the Ar/N2 and the Kr/N2 mixtures a weak band, proving the existence of a 1:1 species Ar·N2 or Kr·N2, was observed near 2326 cm-1. Using spectra recorded at different temperatures, the complexation enthalpy of Ar·N2 was determined to be -1.5(4) kJ mol-1
