Hyperfine Rather Than Spin Splittings Dominate the Fine Structure of the B ⁴Σ^-–X ⁴Σ^- Bands of AIC

Authors

Dennis J. Clouthier, University of KentuckyFollow
Aimable Kalume, University of KentuckyFollow

Abstract

Laser-induced fluorescence and wavelength resolved emission spectra of the B ⁴Σ⁻–X ⁴Σ⁻ band system of the gas phase cold aluminum carbide free radical have been obtained using the pulsed discharge jet technique. The radical was produced by electron bombardment of a precursor mixture of trimethylaluminum in high pressure argon. High resolution spectra show that each rotational line of the 0-0 and 1-1 bands of AlC is split into at least three components, with very similar splittings and intensities in both the P- and R-branches. The observed structure was reproduced by assuming b_βS magnetic hyperfine coupling in the excited state, due to a substantial Fermi contact interaction of the unpaired electron in the aluminum 3s orbital. Rotational analysis has yielded ground and excited state equilibrium bond lengths in good agreement with the literature and our own ab initio values. Small discrepancies in the calculated intensities of the hyperfine lines suggest that the upper state spin-spin constant λ′ is of the order of ≈0.025–0.030 cm⁻¹.

Document Type

Article

Publication Date

1-20-2016

Notes/Citation Information

Published in The Journal of Chemical Physics, v. 144, issue 3, 034305, p. 1-8.

© 2016 AIP Publishing LLC.

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The following article appeared in The Journal of Chemical Physics 144, 034305 (2016) and may be found at https://doi.org/10.1063/1.4939797.

Digital Object Identifier (DOI)

https://doi.org/10.1063/1.4939797

Funding Information

A.K. thanks the Graduate School of the University of Kentucky for the support of a Lyman T. Johnson Fellowship. This material is based upon work supported by the National Science Foundation under Grant No. CHE-1106338.

Repository Citation

Clouthier, Dennis J. and Kalume, Aimable, "Hyperfine Rather Than Spin Splittings Dominate the Fine Structure of the B ⁴Σ^-–X ⁴Σ^- Bands of AIC" (2016). Chemistry Faculty Publications. 89.
https://uknowledge.uky.edu/chemistry_facpub/89