The microwave spectra of chlorobromoacetylene, chloroiodoacetylene, and chlorodiacetylene

Abstract

The microwave spectra of 35Cl-CC- 79Br, 35Cl-CC- 81Br, 37Cl-CC- 79Br, 37Cl-CC- 81Br, 35Cl-CC-I, 37Cl-CC-I, 35Cl-CC-CC-H,and 37Cl-CC-CC-H in natxiral abundance are reported. The molecules were all found to be linear. The structure of chlorobromoacetylene was obtained: r(C-Cl) = 1.628±0.005 Å; r(CC) = 1.209 ± 0.008 Å; r(C-Br) = 1.790 ± 0.005 Å. The quadrupole coupling constants were obtained for the bromine nuclei of chlorobromoacetylene, for the iodine nucleus of chloroiodoacetylene, and for 35Cl of chlorodiacetylene. A least squares treatment yielded the rotational constants, vibration-rotation interaction and l-type doubling constants for several low frequency modes of the three molecules.