Structures of metallocarboranes. VI. Titanium sandwich complex. Crystal and molecular structure of [(CH3)4N]2[(1,6-C2B10H10(CH3)2)2Ti], bis(tetramethylammonium) 4,4'-commo-bis(decahydro-1,6-dimethyl-1,6-dicarba-4-titana-closo-tridecaborate)(2-) at -160.deg.

Syntheses and Structural Characterizations of Ferra- and Cobaltacarborane Complexes Derived from the arachno-6-R-5,6,7-C3B7H12 [R- = NCCH2-, MeOC(O)CH2-, MeC(O)CH2-] Tricarbaborane1

“…A regular docosahedron has one four-coordinate, ten five-coordinate, and two nonadjacent six-coordinate vertices. Structural studies of other 13-vertex metallacaboranes having closo structures, including closo -1-(η-C 5 H 5 )Co-7,9-C 2 B 10 H 12 , [ commo - Ti -(Ti-1,6-Me 2 C 2 B 10 H 10 )] 2- , closo -4-dppe-4-Pd-1,6-C 2 B 10 H 12 , closo -4,4,4-H(PPh 3 ) 2 -2-OMe-4-Ir-1,6-C 2 B 10 H 11 , closo -1,1-(PPh 3 ) 2 -1-H-1,2,4-RhC 2 B 10 H 12 , closo -1-Me-4-Et 3 P-μ 4,6 -Co(PEt 3 ) 2 -μ-(H) 2 -4,1,2-CoC 2 B 10 H 10 and many tungstadicarbaborane complexes, have shown that the metal atoms favor a six-coordinate position but also that there are significant skeletal distortions in these cages. These distortions occur because the atom occupying the second six-coordinate vertex in the docosahedron usually exhibits long distances to one or two of its neighboring atoms, thereby resulting in structures containing one or two quadrilateral faces, rather than the normal trigonal faces found in the polyhedral boranes.…”

Titanium Dicarbollide Complexes. Molecular Structures of (η5-C2B9H11)(C5Me5)TiMe and (η5-C2B9H11)(η5,η1-C5Me4CH2)Ti

“…However, one key issue that was left unresolved in this work is the question of whether 4 − 6 adopt mononuclear or dinuclear structures. We have now succeeded in crystallizing 4 and 5 and have determined their molecular structures by X-ray diffraction …”

Zirconium-Mediated Oxidative Coupling of Carbons-Adjacent nido-Carborane Dianions of the C2B10 System. Synthesis and Structural Characterization of Full-Sandwich High- and Sub-Valent Zirconacarboranes

“…Group 4 metal mediated oxidative coupling reactions of carboranes and boranes, however, have not appeared in the literature yet. One would not expect that coupling of two [ nido -R 2 C 2 B 10 H 10 ] 2- carborane dianions (R = alkyl, aryl) could be mediated by ZrCl 4 , since it was well documented that reactions of MCl 4 (M = Ti, Zr, Hf) with [ nido -R 2 C 2 B 10 H 10 ]Na 2 resulted in the isolation of divalent group 4 metallacarboranes . These results also suggest that high-valent group 4 metallacarboranes cannot be prepared from conventional salt metathesis methods .…”