Metallaborane

In chemistry, a metalloborane is a compound that contains one or more metal atoms and one or more boron hydride.

These compounds are related conceptually and often synthetically to the boron-hydride clusters by replacement of BHn units with metal-containing fragments.

The MB4 cores (M = Fe or Co) of these two compounds adopt structures expected for nido 5-vertex clusters.

These anions function as ligands for a variety of metals, often forming sandwich complexes.

Reaction of this carborane with iron carbonyl sources gives closo Fe- and Fe2-containing products, according to these idealized equations:[6] A further example of insertion into a closo carborane is the synthesis of the yellow-orange solid closo-1,2,3-(CO)3FeC2B4H6: A closely related reaction involves the capping of an anionic nido carborane C2B4H−7 The last reaction is worked up with acid and air.

Structure of (C 5 (CH 3 ) 5 )FeHCo(CO) 3 B 4 H 7 . [ 1 ] Color code: yellow = B, blue = Fe & Co, red = O, gray = C.
Chemical structure of B 4 H 8 Fe(CO) 3 . As is customary for boron hydrides, the lines drawn between B and H do not represent 2-center, 2-electron bonds.
Structure of (Me 4 N + ) 2 [Fe(C 2 B 9 H 11 ) 2 ] 2- , showing only one Me 4 N + . [ 4 ]