Infrared emission spectroscopy and ab initio calculations on VCl

Abstract

The emission spectrum of VCl has been investigated at high resolution in the 3000–19 400 cm −1 region using a 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 VOCl 3 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 Δ–X 5 Δ system of VCl (previously labeled as [7.0] 5 Δ–X 5 Δ ) has been extended by analyzing the rotational structure of some additional bands. A rotational analysis of the 5 Δ 1– 5 Δ 1 , 5 Δ 3– 5 Δ 3 , and 5 Δ 4– 5 Δ 4 subbands of the 0–2, 0–1, 0–0, and 1–0 bands, and the 5 Δ 2− 5 Δ 2 subband of the 0–1 and 0–0 bands has been obtained and molecular constants have been extracted. The 5 Δ 0±− 5 Δ 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.