Rotational spectrum of CD2I2 - An isotopomer of the first molecule containing two iodine nuclei investigated by microwave spectroscopy

摘要

The rotational spectrum of CD2I2 was measured and analyzed by combining results from two different millimeter wave spectrometers. Low-J transitions were measured with a free jet spectrometer at conditions of completely resolved hyperfine structure over the frequency range 59-69 GHz. High-J rotational transitions were measured at room temperature at frequencies 167-338 GHz and for J " up to 190 ". Spectroscopic constants in the sextic rotational Hamiltonian of CD2I2 have been determined, and the analysis of the observed hyperfine structure yielded all components in the inertial and in the principal nuclear quadrupole coupling tensors for the iodine nuclei. The rotational constants for CD2I2 and those for CH2I2 from Z. Kisiel, L. Pszczolkowski, W. Caminati, and P. G. Favero (1996. J. Chem. Phys. 105, 1778-1785) have been used to evaluate a full r(o) structure and have been combined with the results of ab initio calculations to also evaluate the average r* structure: r(CI) = 2.1364(6) Angstrom, r(CH) = 1.078(2) Angstrom, angle(ICI) = 113.83(5)degrees, and angle(HCH) = 113.3(3)degrees. The current results complete the first analysis of a rotational spectrum of a molecule containing two iodine nuclei. (C) 1998 Academic Press. [References: 20]