Fourier Transform Infrared Emission Spectroscopy of the C4Delta-X4Phi System of ZrCl.

The high-resolution spectrum of ZrCl has been investigated in emission in the region 3000-10 000 cm-1 using a Fourier transform spectrometer. The bands were excited in a microwave discharge through a flowing mixture of ZrCl4 and helium. New ZrCl bands observed in the interval 3600-4400 cm-1 have been assigned to a new C4Delta-X4Phi electronic transition. Four bands with R heads at 4305.7, 4208.0, 4064.7, and 3897.4 cm-1 have been assigned as the 0-0 bands of the 4Delta1/2-4Phi3/2, 4Delta3/2-4Phi5/2, 4Delta5/2-4Phi7/2, and 4Delta7/2-4Phi9/2 subbands. A rotational analysis of the 0-0, 1-1, and 2-2 vibrational bands of the four subbands has been obtained and molecular constants have been extracted. Although there is no proof that the lower 4Phi state is the ground state of ZrCl, we have labeled this transition as C4Delta-X4Phi, consistent with the corresponding near-infrared transition of TiCl (R. S. Ram and P. F. Bernath, J. Mol. Spectrosc., in press). Copyright 1997 Academic Press. Copyright 1997Academic Press