Vibration–rotation spectrum of the acetylene-nitrous oxide van der Waals complex in the 3 micron region

Abstract

Infrared laser absorption spectroscopy has been carried out on a molecular beam containing the HCCH-N2O van der Waals complex. Analysis of the vibration-rotation spectrum gives ν=3281.5437(2) cm−1, A″=9387(1) MHz, A′=9382(1) MHz, B″=2829.6(3) MHz, B′=2827.2(3) MHz, C″=2166.6(2) MHz, and C′=2163.7(2). These rotational constants describe a planar complex with parallel monomer axes making right angles with the vector connecting the monomer centers of mass. The monomer center of mass separation is 3.307 Å. This geometry is very similar to that of HCCH-CO2. This similarity is also present in the comparison of model potential functions calculated for HCCH-N2O and HCCH-CO2.