HYPERFINE AND ZERO-FIELD SPLITTINGS IN THE $^{6}\Sigma$ CrCu MOLECULE

Author Institution:The metal-metal bond in CrCu molecule has been Investigated via ESR spectroscopy at $4^{\circ} K$ . The molecule was produced by the simultaneous deposition of the Separately vaporized metals into solid argon or krypton matrices at $4^{\circ} K$ . Fine structure in the spectrum established that the ground electronic state is $^{6}\Sigma$ with a zero-field-splitting parameter $|D| = 0.003(1)$ $cm^{-1}$ $^{63}Cu$ hyperfine and quadrupole coupling constants are $|A_{\perp}| = 860(10), |A_{11}| = 430(60)$, and |eqQ| = 400(100) MHz, with $g_{\perp} \equiv g_{11} \equiv g_{e}$. $^{53}Cr$ hyperfine structure was unresolved. The anisotropy and the decreased magnitude of the Cu hyperfine relative to the Cu atom indicates bonding via the s electrons with participation of d\`{s} orbitals