Microwave spectrum and structure of the (CO2)2N2O complex

Abstract

The structure of the weakly bound complex (CO2)2N2O has been determined. The spectra of seven isotopic species have been measured by pulsed nozzle Fourier transform microwave spectroscopy. The rotational constants for the normal species are A = 1597.458(3) MHz, B = 1232.969(2)MHz and C = 831.095(1)MHz. The structure resembles a cylinder with the three monomers roughly parallel to each other and is similar to the observed structures of (CO2)2OCS and (OCS)2CO2. The CC distance is 3.521(9) Å, and the CN distances are 3.427(9) Å and 3.638(8) Å. The dipole moment components for the normal species are μa = 0.16(4) D, μb = 0.14(5) D and μc = 0.130(2) D. The total dipole moment is 0.25(4) D. The structure of the complex is predicted quite well with a semi-empirical model that uses distributed multipole moments to represent the electrostatic charge distribution and atom—atom terms to describe dispersion and repulsion.