Metalloborane derivatives with

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-... 

In constrast to the previous section, the literature in this area over the period of the review was dominated by metalloheteroborane (mainly metallocar-borane) chemistry, narrowly focussed on charge-compensated carbollide C2B9H10L derivatives, with relatively few examples of metalloboranes. In... 

Professor Greenwood has provided routes to metalloboranes which are derived from the noble metals Pt and Ir and the nido-B9H12 ", arachno-B9H1A, and closo-BioH102 ions. We wish to make note of some new reactions of Ir and Rh complexes with the arachno-B< H9 ion and compare these results with his observations of arachno-B9H14. ... 

In addn to these methods the Grignard reaction can be employed. For example, decaborane will react with a methyl Grignard and produce the product expected or it will react with double Grignard reagents to produce a cyclic deriv(Ref 28). Metalloboranes can be prepd from metal a-malgams, as illustrated by the following reactions (Ref 3) ... 

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

Borane Anions and their Derivatives.—number of rules, analogous to the 18-electron rule of organo-transition-metal chemistry, have been proposed for metalloboranes. Thus, (i) a closo-, n-vertex polyhedral heteroborane with one transition-metal vertex requires 2n 4- 14 electrons, (ii) niWu-polyhedra of this type require 2 + 16 electrons, and (iii) c/ojo-polyhedra with two transition-metal vertices require 2n + 26 electrons. Further rules can also be derived for cowwo-compounds in which two c/ojo-polyhedra are fused at the metal atom. ... 

The metal carbonyl clusters - They have been characterized by X-ray diffraction with nuclearities up to the range 30 to 40, by the pioneering work of Chini. They are neutral or, mono-, di-, or trianionic, and these anions can be protonated to give respectively mono-, di- or trihydrides. They have been much studied by organometallic chemists who have used them as models of the Fischer-Tropsch reaction and replaced some carbonyls by unsaturated hydrocarbon ligands. Wade has compared them to metalloboranes, which allowed him to propose a new, correct electron count. Metallocarboranes, derived from the latter, were introduced by Hawthorne. 

---