BI-METALLIC MOLECULES: ESR OF MANGANESE-AND CHROMIUM-CONTAINING SPECIES

$^{1}$R.J. Van Zee and W. Weltner, Jr., J. Chem Phys. 74, 4330 (1981); erratum 75 2484 (1981).The molecules NaCr, CrAg, CrAu $(^{6}\Sigma)$ and MnAg, CrZn $(^{7}\Sigma)$ were observed in argon and krypton matrices at $4^{\circ} K$. Those containing noble metals showed hyperfine splittings (hfs) for these nuclei, providing a description of the distribution of the unpaired electrons. MnAg was well characterized by observation of hfs for both nuclei: $A_{iso} (^{55}Mn)-244(40)MHz$, and $A_{iso}(^{107}Ag)-120 (20)$ Mhz, but interestingly, neither MnCu nor MnAu was detected. In CrAg and CrAu, no chromium and only small noble metal $[A_{igo}(Ag, Au)< 50 MHz]$ hfs were observed. As in $CrCu^{1}$, nuclear quadrupole effects are seen in CrAu. The information obtained in these experiments should help to clarify our understanding of metal-metal bonding in high-spin diatomics