Multiple-bond character between two carborane polyhedra: the two-electron reduction of biscarborane

Synthesis and crystal structure of an assembly of three ortho‐carborane cages linked via para‐phenylene units: effect of aryl orientation on cage CC bond lengths in C‐aryl‐ortho‐carboranes

“…Extreme variations in cage C1-C2 bond lengths attributable to exo π -bonding have been noted previously, e.g. in the dianion [C 2 B 10 H 11 ] 2− 2 , in which a carbon-carbon double bond links two carborane cages, 54,55 in anions [PhCB 10 H 11 CX] − (X = O or S) 56,57 and in species (RS) 2 C 2 B 10 H 10 . 58…”

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

“…Far more dramatic effects of C-X exo-dative -bonding on cage geometries, particularly on cage C1-C2 distances in derivatives of ortho-carborane, have been found in other systems RCb o X (Fig 1(a)), e.g. in Hawthorne's studies 9,10 PhCH is linked to C1 by an exo C=C double bond (Fig 1(a), R = PhCH 2 , X = PhCH . [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.…”

A photoelectron spectroscopic and computational study of the o-dicarbadodecaborane parent anion

“…2− are thought to be connected double cages with a single negative charge on each cage. 16,17 Also, (C 2 B 10 H 12 ) − has been observed to be in equilibrium with (C 2 B 10 H 10 RR ′ ) − in mixtures of (C 2 B 10 H 12 ) 2− and C 2 B 10 H 10 RR ′ in solution. 13 There have also been a few anionic-related studies of o-carborane in isolation, i.e., in vacuo.…”