ScNi and TiCo Molecules

The isoelectronic ScNi and TiCo molecules have been trapped in argon matrices near 4 K and their electronic ground states established as 2∑ via electron spin resonance (ESR) spectroscopy. These ground states are indicative of multiple metal—metal bonding. The hyperfine splittings at the 47Ti59Co nuclei indicate an approximate 3dσ_Ti0.33 + 4sσ_Ti0.33 + 3dσ_Co0.07 + 4sσ_Co0.25 unpaired electron configuration. Likewise the 45ScNi nuclear hyperfine interactions indicate an approximate 3dσ_Sc0.50 + 4sσ_Sc0.35 + (4sσ + 3dσ)_Ni0.15 configuration. The spin dis­tribution, electronic structures, and bonding in these molecules are dis­cussed relative to the Brewer-Engel theory of metals and to calculations made on such alloy systems. It may be inferred from these results that the ScCo, TiFe, TiNi, and VCo molecules probably have 1∑ multiply bonded ground states.