1-Diphenylphosphino-2-methyl-1,2-dicarba-closo-dodecaborane(12)

Abstract

Two C atoms from two phenyl groups and one C atom of the 2-methyl-1,2-dicarba-closododecaborane cage in the title compound,

Sulfur, tin and gold derivatives of 1-(2′-pyridyl)-ortho-carborane, 1-R-2-X-1,2-C2B10H10(R = 2′-pyridyl, X = SH, SnMe3or AuPPh3)

“…21 The crystal The π orbital overlap between phenyl group and tangential cluster orbitals has been invoked to explain the cage C-C lengthening in aryl-ortho-carborane derivatives. 24,25 This was further explored by ab initio RHF/6-31G* and MP2/6-31G* calculational studies on 1-phenylortho-carborane and other aryl-carboranes in order to probe the orientational preferences of aryl groups attached to the carbon atoms of ortho-carborane. 26,27 These calculations have indicated that, although the overall energy of an aryl-carborane may vary only slightly with the aryl group orientation, the latter does have a perceptible influence on the C(1)-C(2) bond distance, which is greatest when the aryl group is aligned perpendicular to the aryl C-C(1)-C(2) plane.…”

Exo-π-bonding to an ortho-carborane hypercarbon atom: systematic icosahedral cage distortions reflected in the structures of the fluoro-, hydroxy- and amino-carboranes, 1-X-2-Ph-1,2-C2B10H10 (X = F, OH or NH2) and related anions

“…[12][13][14][15][16][17] Welch carried out systematic studies of aryl-ortho-carboranes bearing substituents of varied bulk 4 on the second carbon atom, enabling him to document both the steric and subtle electronic effects on the cage C1-C2 distance. 12,13,14,15 Teixidor and Viñas, in extensive studies 16 on thiolato (RSCb o R') and phosphino (R 2 PCb o R') derivatives of orthocarborane, found the cage C1-C2 distances varied in a manner they attributed to steric and electronic factors and, more recently, 17 to exo C-X -bonding effects such as we advocate below.…”

Preparative and structural studies on sulfur-linked carborane icosahedra: 2-Phenyl-ortho-carboranyl-sulfur systems (2-Ph-1,2-C2B10H10)2X (X=S, S2 or SO), and ortho-carboran-di-yl systems (1,2-C2B10H10Y)2 (Y=S or SO)

“…A perpendicular orientation minimises non-bonding repulsions with the other substituent on C(12), and maximises the opportunity for dative π-bonding from the π-system of the phenyl group to the carborane cage. 16,17 The cage carbon-carbon distance, C(1)-C(2), of ortho carborane is the cage edge link known to be most sensitive to the presence of π-bonding substituents on the cage hypercarbon atoms. 11,18,19 Its length increases as exo π-bonding increases.…”