Elucidating Au-C Bonding via Laser Spectroscopy of Gold Monocarbide
physics.atom-ph
/ Authors
/ Abstract
Gold monocarbide (AuC) has been produced and characterized using laser spectroscopy, representing the first reported observation of AuC. We recorded the optical spectrum of gas-phase AuC between 400 nm and 700 nm, assigning excitations from the $\mathrm{X}\,^2Π_{1/2}( (2σ)^2 (2π)^1 )$ ground state to states arising from the $(2σ)^2 (3σ^\ast)^1 $ and $(2σ)^1 (2π)^2 $ configurations. Dispersed-fluorescence spectra are used to study the vibrational and spin-orbit structure of the ground state, branching ratios and radiative lifetimes of the excited states, and the Au--C bond dissociation energy. A molecular orbital diagram is used to rationalize the nature of AuC's low-lying electronic states. The data serve as valuable benchmarks of relativistic theory and are relevant to quantum science and precision measurements with cold molecules.