Laser velocity modulation spectroscopy of TiCl+: Observation of the A 3Δ(3d2) state and deperturbation of the X 3Φ−A 3Δ complex

Abstract

A single mode cw dye laser along with velocity modulation was used to record weak bands of TiCl+ in the spectral region 17 100–18 600 cm−1. The ions were produced in the positive column of an ac glow discharge with a gas mixture of He/TiCl4. These new bands have been identified as linking the upper already known [17.8]3Δ(3d4s) state to respectively the X 3Φ(v=1) state and to a newly observed A 3Δ(v=0) state located 350 cm−1 above the X 3Φ(v=0) state. As suggested by Focsa et al. (J. Chem. Phys. 106, 9044 (1997)) the A 3Δ(3d2) state was found to be responsible for the perturbations observed in the X 3Φ(3d2) state. The spin-orbit components of the A 3Δ(v=0) and the X 3Φ(v=1) states revealed interaction leading to homogeneous and heterogeneous perturbations. A set of deperturbed parameters has been determined with the help of a full matrix-based handling of the A 3Δ(v=0) and the X 3Φ(v=0,1) states. Study of the contributions of the basis functions to the eigenvectors of the diagonalized matrix displayed evidence of a reversal of the leading character of the Ω=3 spin-orbit components of the A 3Δ(v=0) and the X 3Φ(v=1) states. A remarkable example of avoided crossing has been observed between the A 3Δ1(v=0) and the X 3Φ2(v=1) spin-orbit components.

UV Laser Spectroscopy Using the Velocity-Modulation Technique: New Hot Bands of the B2Σ+u–X2Σ+g System of N+2

“…In the case of the (5, 3) band, no extra -line was observed and we could not confirm, in the UV range, the presence of the only extra -line reported in the visible by (13). In the case of the (2, 0), (4, 2), (6,4) and (8,6) bands, the extra -lines are expected to be observed at N Ͼ 35, higher than the value reached on our spectra. The analysis of the spectra of the (2, 0), (4, 2), (6, 4), and (8, 6) bands did not bring any new improvement in the determination of molecular parameters of the upper vibrational levels.…”

“…At first, in 1928 Herzberg observed the (2, 0), (3,1), and (4, 2) bands at low resolution (24). Then in 1932, Coster and Brons (25) recorded the (8,6) band. Even if they were able to analyze the rotational structure, their resolution was too low to obtain a good set of parameters.…”

“…[8] and the value of the constants and which are opposite in sign (Table 3), it turns out that the value of the coupling element increases continuously in J for the e levels, whereas it becomes minimum at J ϳ 10.5 for the f levels. Therefore at the avoided crossing point, the perturbation will be weak and punctual between the f components and strong over a wide range between the e components, respectively.…”

“…Up until now, it has mainly been used in the infrared region, namely in the groups of Davies at Cambridge, Oka at Chicago, Saykally at Berkeley, and also occasionally in the far-infrared (1) and in the visible range namely for studying N 2 ϩ (2-6). Very recently we have studied TiCl ϩ (7)(8) and TiF ϩ (9), through their electronic spectra in the visible range, as well as H 2 O ϩ (10) and N 2 ϩ (11-12) in the near-infrared region. However, the availability of UV cw laser sources, continuously tunable over a wide range, makes the study of electronic transitions of molecular ions in this region also very attractive.…”

Velocity modulation spectroscopy of molecular ions I: The pure rotational spectrum of TiCl+ (X3Φr)

“…Kaledin and Heaven [10] then conducted further measurements of the [17.9] 3 D r -X 3 U r and [17.9] 3 D r -(1) 3 D r transitions with associated LFT calculations, which predicted nearby 3 R and 3 P states. The most recent work is by Focsa et al [11,12] and Focsa and Pinchemel [13]. In the Focsa et al [11] study, the [17.9] 3 D r -X 3 U r (v = 0 and 1) and the [17.9] 3 D r -A 3 D r systems were measured.…”