High Resolution Laser Spectroscopy of Rhodium Monophosphide A

High Resolution Laser Spectroscopy of Rhodium Monophosphide A. G. Adam *, M. E. Slaney *, L. E. Downie *, R. Li ‡, W. J. Balfour ‡ Centre for Laser, Atomic, and Molecular Sciences, University of New Brunswick, Fredericton, NB, E 3 B 6 E 2 *Dept. of Chemistry, University of New Brunswick, Fredericton, NB, E 3 B 6 E 2 ‡Dept. of Chemistry, University of Victoria, BC, V 8 W 3 V 6

Wilkinson’s Catalyst Rhodium Monophosphide

Previous Work • Medium resolution study by Balfour et al. [J. Phys. Chem. A 108, 8145 -46 (2004)] – – Partial rotational resolution Dispersed fluorescence Lifetimes Ground state electronic configuration of …σ2π4δ 4σ2 • Recent theoretical study of triple-bond covalent radii by Pykkö et al. [Chem. Eur. J. , 11, 3511 -20 (2005)] – Prediction of Rh. P bond length: r = 1. 982Å

Pulsed Laser Survey Scan

Dispersed Fluorescence Analysis

Deslandres Tables (from excitation spectra) * * * * * • Variation in vibrational spacing. • Ground State vibrational progression (507, 502, 498, 492, 488 cm-1) gives: ωe= 500. 33 cm-1, ωexe = 2. 07. • Low lying electronic states at 2454 and 4691 cm-1.

Pulsed Laser Survey Scan

High Resolution Analysis P Branch = Red R Branch = Green

Perturbations High resolution spectrum of the [22. 8]1Σ+–X 1Σ+(1, 0) transition with perturbations at P(18) and R(16).

Perturbations High resolution spectrum of the [22. 8]1Σ+–X 1Σ+(0, 0) transition with perturbations at P(15) and R(13).

Reduced Term Value Plot

Rotational Constants

Equilibrium Molecular Constants

Conclusions • • Spectra have been observed and acquired in high resolution for four families of bands at 19628, 21672, 23183, and 23742 cm-1 above the ground state. All states are of 1Σ+ symmetry. Dispersed fluorescence of all bands allowed for a determination of ground state vibrational constants. Molecular constants for the ground state and four excited states have been determined from a global least squares fit. W. Balfour has analyzed 17 other bands (some v"=0, some v"=1) using the high resolution ground state molecular constants.

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