Infrared emission spectroscopy and ab initio calculations on VCl

The emission spectrum of VCl has been investigated at high resolution in the 3000 - 19 400cm(1) region using it Fourier transform spectrometer. The bands were excited in a high temperature carbon tube furnace by the reaction of vanadium metal vapor and a trace of BCl(3)as well as in a microwave discharge lamp by the reaction of VOCl3 vapor with active nitrogen, The spectra were recorded using the Fourier transform spectrometer associated with the McMath Pierce telescope of the National Solar Observatory at Kitt Peak. The analysis of the E(5)Delta-X(5)Delta system of VCl (previously labeled as [7.0](5)Delta - X-5 Delta) has been extended by analyzing the rotational structure of some additional bands. A rotational analysis of the 5Delta(1), 5Delta(1) 5Delta(3) 5Delta(3), and (5)Delta(4) 5Delta(4) subbands of the 0 2, 0 1, 0-0, and 1-0 bands, and the (5)Delta(2) - 5Delta(2) subband of the 0-1 and 0-0 bands has been obtained and molecular constants, have been extracted. The (5)Delta(0+/-) - (5)Delta(0+/-) subband was not identified in any of the assigned bands. The spectroscopic properties of the low-lying electronic states of VCl have been predicted by CASSCF/CMRCI ab initio calculations and the experimental assignments are supported by the ab initio results. (C) 2003 Elsevier Science (USA). All rights reserved.