A Diamondoid Network of Tetrakis(acetamidato)dirhodium in Mixed Oxidation States Linked by μ₄-Iodide Having a 10⁵ Enhancement of Its Electrical Conductivity by Water Molecules of Hydration

A mixed oxidation-state (Rh24+ and Rh25+) compound, [{Rh2(acam)4}2I]n·6nH2O (Hacam = acetamide), has been synthesized. The compound has a nonpenetrating diamondoid arrangement of {Rh2(acam)4} units linked by μ4-iodides. All of the dirhodium units are crystallographically equivalent, as are all of the iodide atoms. The magnetic susceptibility of this compound shows that one-half of the Rh2 units are in the Rh25+ oxidation state with one odd electron and the other half in the closed-shell Rh24+ state. Its electrical conductivity is 1.4 × 10-3 S cm-1 (pellets, room temperature) and oscillates over the range of 105 orders of magnitude during dehydration−rehydration cycles of interstitial water molecules.