Cobalt complexes carborane

It is not necessary to start with the protonated Fe(II) complex to isolate these substituted products, however. Reaction of a slurry of the unsubstituted Fe(III) complex with anhydrous HC1 in diethyl sulfide produced a mixture of substitution products, including the species shown in Eq. (12). Although no evidence has been found for a protonated cobalt metallo-carborane analog, boron-substituted complexes of cobalt (III) may also be obtained by reaction of the (1,2-C2B9Hn)2Co- ion with R2S and HC1 52). 

Carboranes also offer the capacity for Co111—C bond formation. Perhaps the best-known example of a mixed cyclopentadienyl-metallocarborane sandwich complex is the cobalt(III) compound (Cp)Co(l,2-C2B9Hn), which serves as a precursor for other species.544... 

Curiously, only chromium (33), cobalt, and nickel complexes of this 11-atom ligand have been prepared thus far. The complex (l,7-B9C2Hu)2Co has been prepared by both the anhydrous and aqueous methods (18). An X-ray diffraction study of the cesium salt of the cobalt(III) complex confirmed the symmetrical sandwich bonding of the carborane cages but failed to locate the carbon atoms because of disorder in the crystal (48). 

Although mixed carborane-cyclopentadienyl complexes, predominantly those of cobalt, are the metallocarboranes that have received the most... 

Carborane-metal complexes, 8, 87-113 Catalysis by organometallics carbonylation, 6, 158-163 hydroformylation, 6, 128-136 olefin reactions, 7, 199-202 organic syntheses by nickel compounds, 8, 48-83 reviews, 10, 331-336 Cationic metal carbonyls, 8, 117-159 Chromium carbonyls, 8, 133-159, see also Benchrotrenes Cobaloximes, 7, 161, 203 Cobalt carbonyl, 6, 119-163 8, 152-155 Cotton-Kraihanzel method, 10, 213-214 Coupling reactions, on nickel, 8, 30-39, 82-83... 

Another series of carborane anion complexes of transition metals is formed from the B7C2H ion.32 For example, when the B7C2Hjf ion mentioned in Section 8-11 is treated with cobalt(n) chloride, the following reaction occurs 2B7C2H r + 1.5Co2+ - t(B7C2H9)2Co]- +0.5Co + 2H2 32 T. A. George and M. F. Hawthorne, J. Amer. Chem. Soc., 1969, 91, 5475. 

An increasing volume in the literature is devoted to pseudo-cyclopentadienes and pseudo--arenes. A general paper describes complexation of the cyclo-Ps anion. The synthesis of the first diazacobaltocene has been described. Tert-butyl-substituted diazaferrocenes have been prepared from substituted pyrroles. Bis-(borole)nickel complexes have been prepared from dilithium txnelediides. Carborane stabilised iron indole and iron thiophene complexes have been made. The electrophilic stacking of borataferrocene and bis(borole)cobaltate ions with -Cr(CO)3 and Mn(00)3 has been described. The synthesis and crystal structure of... 

Recently, some other boron carriers were used to deliver polyhedral boranes into tumor cells. One of the most interesting and new direction is developments in the BNCT driven by nanotechnology [142-147]. This subject will not be discussed here since a special chapter is planned in this book. Carboranylquinazolines [148], carboranyl aminoalcohols [149], carboranyl-a-acyloxy-amides [150], carboranyl glycophosphonates [151], conjugates of icosahedral dicarboranes with cobalt bis(dicarbollide) [152], and platinum complexes containing carborane [153] have been obtained as potential candidates for BNCT. 

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