Cobalt-Hydrogen Metallocarboranes. Synthesis of Closo- ((CH 3)2C2B4H4)2CoH and Nido-Closo-((CH3)2C2B3H5)CoH((CH3)2C2B4H4) and Their Conversion to New Cobalt-Cobalt Bonded Metallocarboranes.
Interim technical rept.,
VIRGINIA UNIV CHARLOTTESVILLE DEPT OF CHEMISTRY
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The reaction of NaCH32C2B4H5- with CoCl2 at 25C yields the red neutral commo-metallocarborane C,C-CH32C2B4H42CoIIIH. From NMR evidence the hydrogen atom associated with the metal is proposed to be face-bonded to a triangular face on the polyhedral surface. The compound is converted in aqueous acid to a nido-closo species, C,C-CH32C2B3H5CoHC,C-CH32C2B4H4, which in turn can be metal-deprotonated by NaH to give the CH32C2B3H5CoCH32C2B4H4- ion reaction of the latter species with aqueous HCl regenerates the neutral metal-protonated compound. The reaction of the ion with CoCl2 and NaC5H5 produces nido-closo CH32C2B3H5CoHCH32C2B3H3Coeta to the 5th power-C5H5 in which a Co-Co bond is postulated. Treatment of C,C-CH32C2B4H42CoIIIH with eta to the 5th power-C5H5CoCO2 yields 4,5 - CH32-1,2,4,5-eta to the 5th power-C5H52Co2C2B3H3 and eta to the 5th power-C5H5CoCH32C2B3H3CoHCH32C2B3H3Coeta to the 5th power-C5H5, the latter species having a proposed Co-Co link. Air-oxidation of C,C-CH32C2B4H42CoIIIH produces the tetracarbon carborane CH34C4B8H8.
- Organic Chemistry