Opening of Carborane Cages by Metal Cluster Complexes: The Reaction of a Thiolate-Substituted Carborane with Triosmium Carbonyl Cluster Complexes

Abstract

The reaction of Os3(CO)10(NCMe)2 with closo-o-(1-SCH3)C2B10H11 has yielded the complex Os3(CO)9[μ3-η(3)-C2B10H9(SCH3)](μ-H)2, 1, by the loss of the two NCMe ligands and one CO ligand from the Os3 cluster and the coordination of the sulfur atom and the activation of two B-H bonds with transfer of the hydrogen atoms to the cluster. Reaction of 1 with a second equivalent of Os3(CO)10(NCMe)2 yielded the complex Os3(CO)9(μ-H)[(μ3-η(3)-1,4,5-μ3-η(3)-6,10,11-C2B10H8S(CH3)]Os3(CO)9(μ-H)2, 2, that contains two triosmium triangles attached to the same carborane cage. The carborane cage was opened by cleavage of two B-C bonds and one B-B bond. The B-H group that was pulled out of the cage became a triply bridging group on one of the Os3 triangles but remains bonded to the cage by two B-B bonds. When heated to 150 °C, 2 was transformed into the complex Os3(CO)9(μ-H)[(μ3-η(3)-μ3-η(3)-C2B10H7S(CH3)]Os3(CO)9(μ-H), 3, by the loss of two hydrogen atoms and a rearrangement that led to further opening of the carborane cage. Reaction of 1 with a second equivalent of closo-o-(1-SCH3)C2B10H11 has yielded the complex Os3(CO)6)(μ3-η(3)-C2B10H9-R-SCH3) (μ3-η(3)-C2B10H10-S-SCH3)(μ-H)3, 4a, containing two carborane cages coordinated to one Os3 cluster. Compound 4a was isomerized to the compound Os3(CO)6(μ3-η(3)-C2B10H9-R-SCH3)(μ3-η(3)-C2B10H10-R-SCH3)(μ-H)3, 4b, by an inversion of stereochemistry at one of the sulfur atoms by heating to 174 °C.

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

“…Metalation of boron vertices of icosahedral carborane clusters generally occurs upon coordination of a late transition metal to a directing donor group, 11 although rare examples of unsupported exohedral metal–boron bonds have been reported as well. 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.…”

“Broken-hearted” carbon bowl via electron shuttle reaction: energetics and electron coupling

“… 60–62 For that, we used a triosmium carbonyl complex, Os 3 (CO) 10 (NCMe) 2 ; however, no ring-opening of corannulene was observed, while successful o -carborane opening occurred at 150 °C in a nonane reflux. 62 …”

“…[60][61][62] For that, we used a triosmium carbonyl complex, Os 3 (CO) 10 (NCMe) 2 ; however, no ring-opening of corannulene was observed, while successful ocarborane opening occurred at 150 C in a nonane reux. 62 Further experimental investigations were pursued to rule out aromaticity stabilization as a main factor by performing reactions with signicantly less strained PAHs including pyrene (0.0 kJ mol À1 ) 31 or phenanthrene (0.0 kJ mol À1 ) 63 under experimental conditions similar to those used for the reaction with highly-strained corannulene (101 kJ mol À1 ; 31 see ESI † for more details). As a result, no bond cleavage was detected in any of these systems, and formation of only PAH$TCNQ complexes was observed (e.g., phenanthrene$TCNQ complex (similar to the structure reported in the literature 64 ) or pyrene$TCNQ complex, Fig.…”

A simple and high-yield route to iridium, rhodium, osmium and rutheniumnido-6-metalladecaborane compounds

“…36 We can also appreciate the potential of polyhedral "Bframes" for the construction of multimetallic species, in more recently reported complexes such as Os 3 (CO) 9 [(C 2 B 10 H 8 ](H) 2 and Os 3 (CO) 9 (H)[(C 2 B 10 H 8 S(CH 3 )]Os 3 (CO) 9 (H) 2 , which feature one and two triangular Os 3 clusters, supported on the surface of a twelve-vertex closo-carborane, {C 2 B 10 H 8 } and on an eleven-vertex nido-carborane, {C 2 B 10 H 8 S(CH 3 )}, respectively. 37,38 Compound 6 exhibits an 11-vertex nido structure, which is shown in Figure 4 together with selected distances and angles (Table S3, in the SI, lists additional data). Two metal fragments, {Os(CO)(PPh 3 )} and {Pt(PMe 2 Ph) 2 }, and three {BH} units form an open pentagonal face.…”