Cage Opening of a Carborane Ligand by Metal Cluster Complexes

Abstract

The reaction of Os3 (CO)10 (NCMe)2 with closo-o-C2 B10 H10 has yielded two interconvertible isomers Os3 (CO)9 (μ3 -4,5,9-C2 B10 H8 )(μ-H)2 (1 a) and Os3 (CO)9 (μ3 -3,4,8-C2 B10 H8 )(μ-H)2 (1 b) formed by the loss of the two NCMe ligands and one CO ligand from the Os3 cluster. Two BH bonds of the o-C2 B10 H10 were activated in its addition to the osmium cluster. A second triosmium cluster was added to the 1 a/1 b mixture to yield the complex Os3 (CO)9 (μ-H)2 (μ3 -4,5,9-μ3 -7,11,12-C2 B10 H7 )Os3 (CO)9 (μ-H)3 (2) that contains two triosmium triangles attached to the same carborane cage. When heated, 2 was transformed to the complex Os3 (CO)9 (μ-H)(μ3 -3,4,8-μ3 -7,11,12-C2 B10 H8 )Os3 (CO)9 (μ-H) (3) by a novel opening of the carborane cage with loss of H2 .

(BB)-Carboryne Complex of Ruthenium: Synthesis by Double B–H Activation at a Single Metal Center

“…12 We have recently prepared rhodium complexes of the novel POBOP (POBOP = 1,7-OP( i -Pr) 2 - m -carboranyl) pincer ligand containing strained exohedral metal–boron bonds, which were enforced by the unusual geometry of the three-dimensional carborane cage and chelating phosphinite arms. 4p The close contact between the metal center and the vicinal B–H bond of the carborane cage led to a cascade transformation, which resulted in the transfer of the metal center to the adjacent boron atom of the cage.…”

Expansion of the (BB)Ru metallacycle with coinage metal cations: formation of B–M–Ru–B (M = Cu, Ag, Au) dimetalacyclodiboryls

“…The results reported herein uncover unusual reactivity of the ruthenium BB-carboryne with inorganic electrophiles and introduce a new approach for the rational construction of multimetallic complexes supported on the surface of polyhedral boron cages. 11 , 117 These compounds are the first examples of coordination of electrophilic metal cations to the 2c-2e exohedral metal–boron bonds of boron clusters. The best representation of bonding in 2-Cu and 2-Ag complexes is the 3c-2e B–M···Ru interaction description that is often used for bridging B–H···M interactions in boranes and boron clusters while bonding in 2-Au is closer to the localized 2c-2e Au–B bond.…”

Synthesis of 13-vertex dimetallacarboranes by electrophilic insertion into 12-vertex ruthenacarboranes

“…A similar opening upon exo-coordination has been recently observed for carborane-Os3 clusters. 29 The insertion proceeds via a transition Fig. 9 The optimized structures of 13-vertex boranes and carboranes.…”