An improved evaluation of the equilibrium structure of cyanogen iodide

The millimetre-wave spectra of (IC)-C-12 N-14 in the 10(0)0, 02(0)0 and 02(2)0 vibrational stales were measured. A more precise equilibrium rotational constant was calculated and a new evaluation of the equilibrium structure of cyanogen iodide was made by using the B-e values of three different isotopomers. The following results were obtained: r(e)(C-I) = 1.99202 +/- 0.00006 Angstrom and r(e)(C-N) = 1.16055 +/- 0.00009 Angstrom. The ground-state millimetre-wave spectrum of (ICN)-C-13-N-15 was also recorded, and the substitution structure of cyanogen iodide was calculated from four different parent molecules. (C) 1998 Elsevier Science B.V.