title: Nonpolar nitrous oxide dimer: observation of combination bands of (14N2O)2 and (15N2O)2 involving the torsion and antigeared bending modes.
abstract: Spectra of the nonpolar nitrous oxide dimer in the region of the N(2)O ν(1) fundamental band were observed in a supersonic slit-jet apparatus. The expansion gas was probed using radiation from a quantum cascade or a tunable diode laser, with both lasers employed in a rapid-scan signal averaging mode. Four bands were observed and analyzed: new combination bands involving the intermolecular conrotation of the monomers (A(g) antigeared bend) for ((14)N(2)O)(2) and ((15)N(2)O)(2), the previously reported torsional combination band for ((14)N(2)O)(2) with improved signal-to-noise ratio, and the same torsional combination band for ((15)N(2)O)(2). The resulting frequencies for the intermolecular antigeared mode are 96.0926(1) and 95.4912(1) cm(-1) for ((14)N(2)O)(2) and ((15)N(2)O)(2), respectively. This is the third of the four intermolecular frequencies which has now been measured experimentally, the others being the out-of-plane torsion and the geared bend modes. Our experimental results are in good agreement with two recent high level ab initio theoretical calculations.
authors.affiliation: Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Rezaei
authors.forename: K H
authors.initials: KH
authors.lastname: Michaelian
authors.forename: N
authors.initials: N
authors.lastname: Moazzen-Ahmadi