Laser Induced Fluorescence (LIF) spectra of gas-phase rhodium monophosphide, obtained at mediumresolution at the University of Victoria (UVic), have resulted in the assignment of 63 bands to eight different electronic transitions from seven Omega = 0(+) states and one Omega = 1 state to the ground X-1 Sigma(+) state. Rotational analysis of high-resolution spectra of 16 of the bands from four of the band systems, [19.6] 0(+), [21.7]0(+), [22.9]0(+) and [23.4]0(+)-X-1 Sigma(+), obtained at the University of New Brunswick (UNB), yielded a ground state bond length, r(e) = 1.999315(58) angstrom in good agreement with theoretical calculations. Analysis of a perturbation in the [22.9]0(+)-X-1 Sigma(+) (0, 0) band suggested a strong interaction between the [22.9]0(+) v = 0 level and a very close lying Omega = 1 state. All the upper states that were rotationally analysed showed irregular variations with vibration of the vibrational separations, Delta G(v+1/2), and the rotational constants B-v. (C) 2019 Elsevier Inc. All rights reserved.

Laser induced fluorescence spectra of iridium monophosphide, IrP, have been obtained at low and high resolution in the blue region of the visible spectrum. Two electronic transitions were observed with origins near 459.6 and 471.9nm. Three vibronic bands in each of these transitions have been observed at high resolution allowing for full characterization of the states. A J-independent doubling of the rotational lines has been ascribed to nuclear electric quadrupole coupling in the ground state. Multireference configuration interaction (MRCI) calculations have been performed in order to confirm the nature of the ground state and aid in the assignment of the excited states. The two observed transitions have been assigned as the [21.7]1Σ+–X1Σ+ and the [21.2] 3Σ+–X1Σ+ electronic systems based on comparison with the theoretical calculations. The v+2 level of each of these electronic transitions was found to be heavily perturbed and a successful deperturbation analysis was performed allowing for a complete global fit of the data.

The diatomic molecule, chromium monophosphide, has been studied by laser-induced fluorescence in a supersonic beam following laser-ablation of a chromium target in the presence of a small percentage of phosphine doped in helium. Two bands have been analyzed and were assigned as the 0–0 and 1–0 bands of the [14.9]4Σ−–X4Σ− electronic transition. An excited state value of ΔG(12)=332.7341(16)cm−1 was obtained. From dispersed fluorescence, ground state values of ωe=408.0±2.6cm−1 and ωexe=2.2±0.6cm−1 were obtained. The two bands were found to be perturbed, particularly the 0–0 band, but a satisfactory rotational analysis yielded a well-determined set of molecular parameters.

While both the A˜2Π–X˜2Σ+ and C˜2Δ–X˜2Σ+ transitions of CaCCH have been previously reported in laser-induced fluorescence experiments, the B˜2Σ+–X˜2Σ+ transition has remained undetected by this technique. We have applied cavity ring down laser spectroscopy to a pulsed molecular jet containing CaCCH, and have observed an absorption feature that does not fluoresce upon excitation, consistent with the B˜2Σ+–X˜2Σ+ transition.