Metal-Promoted Exopolyhedral Substitution of Terminal Hydrogen Atoms in the Closo-Decaborate Anion [B10H10]2– in the Presence of Copper(II): Formation of the Substituted Derivative [2-B10H9OH]2–

Copper(II) complexation of the [B10H10]2– anion has been studied in the presence of 2,2′-bipyridyl (bipy) in organic solvents. The reaction between CuCl, bipy, and (Et3NH)[Ag[B10H10]] in DMF leads to copper(II) complex [Cu2(bipy)4(µ-CO3)][B10H10]·2DMF·H2O. The copper complexation reaction has been performed under the redox conditions Cu(I)  → Cu(II) in the presence of silver(I) compounds. When [Cu2(bipy)4(µ-CO3)][B10H10]·2DMF·H2O has been heated in DMSO, the monosubstituted derivative [2-B10H9OH]2– has been isolated as complex [Cu2(bipy)4(µ-CO3)][2-B10H10O0.17]·2DMSO·H2O consisting of the [B10H10]2– anion and its monosubstituted derivative [2-B10H9OH]2– cocrystallized in the 0.83:0.17 ratio. The metal-promoted process of exopolyhedral substitution of terminal hydrogen atoms in the [B10H10]2¬ anion in the presence of Cu(II) compounds has been discussed. Complexes synthesized have been studied by elemental analysis, IR, 1H and 11B NMR spectroscopy; the X-ray diffraction studies were performed for [Cu2(bipy)4(µ-CO3)][B10H10]·2DMF·H2O and [Cu2(bipy)4(µ-CO3)][2-B10H10O0.17]·2DMSO·H2O.