HIGH-RESOLUTION INFRARED DIODE-LASER SPECTROSCOPY OF NE-N2O, KR-N2O, AND XE-N2O

The rotationally resolved spectra of the van der Weals complexes Ne-N2 O Kr-N2O, and Xe-N2O have been investigated in the region of the v(3) N2O monomer vibrational band using a diode laser absorption spectromet er that is incorporated with a multipass cell and a pulsed jet. The sp ectra of these three complexes are completely analyzed using a normal asymmetric rotor Hamiltonian, and the effective molecular constants ar e accurately determined for both the ground and the excited vibrationa l states. These results show that, like Ar-N2O. the complexes have a T -shaped confirmation in which the rare gas atom prefers to lie near to the oxygen side of N2O. The band origins of Rg-N2O (Rg = Ne, Ar, Kr, and Xe) are observed to shift by 0.36125, 0.15038, -0.10131, and -0.49 066 cm(-1) from that of the monomer, respectively. These band origin s hifts are well explained by a simple model for the intermolecular pote ntial. (C) 1998 Academic Press.