63748-65-2Relevant academic research and scientific papers
Facile and mild deboronation of o-carboranes using cesium fluoride
Yoo,Hwang,Do
, p. 568 - 570 (2008/10/08)
The o-carborane and substituted derivatives were degrated effectively using cesium fluoride in ethanol under reflux conditions, producing cesium salts of nido monoanions directly in high yield.
Metallacarboranes in Catalysis. 5. Interconversion of closo-Bis(phosphine)hydridorhodacarboranes by Rhodium Transfer between η5-nido-Carborane Anions
Long, Judith A.,Marder, Todd B.,Hawthorne, M. Frederick
, p. 3004 - 3010 (2007/10/02)
Both the hydride and dicarbollide ligands of a series of closo, formally six-coordinate Rh(III), bis(triphenylphosphine)hydrido η5-(nido-C2B9H9RR') complexes were easily replaced by a series of (1-) ligands using thermal reactions.The following trend for ease of displacement of the nido-carborane anion in cage-carbon-substituted complexes has been found: 7,8-disubstituted > 7,8-monosubstituted > 7,8-unsubstituted > 7,9-unsubstituted ca. 2,9-unsubstituted.Kinetic studies of the reaction of (R = Me, R' = H) (IVd) with (1-) (Ia) and (1-) (III) in THF at 29 deg C showed no anion concentration dependence and a common first-order rate constant for the two reactions although in the case of (1-) (II), anion dependence was observed.Similar kinetic studies of the reaction of (IVf) with anions Ia, II, and III in THF at -63 deg C proved these exchanges with exo-nido substrates to be much faster than the reactions involving closo substrates.In the cases of Ia and II, the less stable kinetic product of the reaction, the exo-nido tautomer, was initially observed along with its conversion to the more stable closo tautomer.Analysis of the anion concentration dependence of the rates of these reactions suggested the existence of a spectroscopically invisible intermediate, presumably an isomer of the exo-nido starting complex.Formation of an analogous intermediate appears to be the rate-determining step in reaction of closo-IVd with anions Ia and III.In addition, the dissociation of either PPh3 or nido-carborane anion does not appear to be involved in any of these cage exchange reactions.Anion III was found to be a more effective nucleophile than Ia which, in turn, was more nucleophilic than II.
