Synthesis, crystal structure and electrochemical properties of three isocloso eleven‐vertex ferrocenecarboxylate ruthenaborane clusters

Abstract

AbstractThe reaction of [RuCl2(PPh3)3] with closo‐[B10H10]2− and C5H5FeC5H4COOH (FcCO2H) in refluxing CH2Cl2 solution affords three ruthenaborane clusters: [PPh3(H2O)(FcCO2)RuB10H8Cl] (1), [(PPh3)2ClRu(PPh3)(FcCO2)RuB10H9]·0.5CH2Cl2 (2 × 0.5CH2Cl2) and [PPh3(FcCO2)2RuB10H8] (3). All of these compounds are characterized by FT‐IR, NMR spectroscopic techniques, elemental analysis and single‐crystal X‐ray analysis. They are all based on a closo‐type 1:2:4:2:2 {RuB10} stack with the metal occupying the unique six‐connected apical position and can be considered as having isocloso structures derived from the complete capping of the open face of an arachano geometry to give a completely closed deltahedral cluster. Compounds 1 and 2 both have an exo‐polyhedral ferrocenecarboxylate that is attached with one {RuO} and one {BO} bond each, resulting in one exo‐cyclic five‐membered RuOCOB ring. There is in addition one exo‐polyhedral ruthenium atom bonded to the center {RuB10} cluster via one {RuRu} linkage and two {RuHµB} bridges, which forms a closed exo‐polyhedral tetrahedron configuration in compound 2. Compound 3 has two exo‐polyhedral ferrocenecarboxylates to form two five‐membered RuOCOB rings engendering a symmetrical conformation. All of these new 11‐vertex ruthenaboranes can be considered as having isocloso structures derived from the complete capping of the open face of an arachano geometry to give a completely closed deltahedral cluster. Copyright © 2006 John Wiley & Sons, Ltd.