ELECTRON-ACCEPTOR BEHAVIOR OF 2,4,7,9-TETRACARBA-NIDO-DODECABORANE(12) WITH GROUP-1 AND GROUP-2 METALS - SYNTHESES AND CRYSTAL-STRUCTURES OF [(THF)(4)LI][(SIME(3))(4)C4B8H9] AND [(THF)(2)MG(SIME(3))(4)C4B8H8]
Ns. Hosmane et al., ELECTRON-ACCEPTOR BEHAVIOR OF 2,4,7,9-TETRACARBA-NIDO-DODECABORANE(12) WITH GROUP-1 AND GROUP-2 METALS - SYNTHESES AND CRYSTAL-STRUCTURES OF [(THF)(4)LI][(SIME(3))(4)C4B8H9] AND [(THF)(2)MG(SIME(3))(4)C4B8H8], Organometallics, 15(10), 1996, pp. 2425-2427
The room-temperature reaction between a, THF solution of 2,4,7,9-tetra
carba-nido-dodecaborane-(12) (SiMe(3))(4)C4B8H8 and finely cut excess
lithium or magnesium metal, in the absence of naphthalene and aromatic
solvents, produced either {[(THF)(4)Li][SiMe(3))(4)C4B8H9]} (1) as an
EPR-silent transparent crystalline solid in 41% yield or [(THF)(2)Mg(
SiMe(3))(4)C4B8H8] (2) as an off-white crystalline solid in 88% yield.
While the solid-state structure of I showed a single anionic [(SiMe(3
))(4)C4B8H9](-) unit that was well-separated from a discrete [Li(THF)(
4)](+) cation, the structure of 2 is that of a novel magnesacarborane
in which the carborane cage incorporates both electron-precise and ele
ctron-deficient carbon and boron atoms.