Bonds, metalloborane derivatives

Metalloborane Derivatives with Ligand-Metal Single Bonds... 

Another route to metalloborane derivatives with metal-boron single bonds is the reaction of certain cationic transition metal compounds with borane anions (20). Addition of solid [(C5H5)Fe(CO)2(cyclohexene)]-PFe to an ether solution of NaBioHia at room temperature formed yellow 6-[(C5Hr>)Fe(CO)2]BioHi3 in 50% yield. The pattern of the B NMR spectrum of this derivative was very similar to other 6-substituted deca-borane derivatives, and on this basis it was proposed that an iron-boron single bond had been formed at B(6) of the decaborane cage as illus-... 

By no means do all metallocarboranes have the metal atoms occupying vertices of the basic polyhedra. Apart from many derivatives in which o-bonded metal residues occupy exo sites attached to particular skeletal atoms, several metalloboranes and -carboranes are known in which the metal occupies an edge-bridging site, effectively replacing a bridging hydrogen atom of the parent borane. Many are nido species related to BeHio, for example, the /x-silyl and /i-germyl carboranes. 

Borane Anions and Metallo-derivatives.—Greenwood and Ward have reviewed the synthesis and structures of metalloboranes, with a discussion of metal-boron bonding.29... 

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