Boron halides simple hydrides

In general, the simple metal hydrides are less reactive toward boron halides than the complex aluminum hydrides. Thus LiH gives very little, if any, diborane on direct interaction with, for example, BF3 or BBr3 at temperatures as high as 180 C (279). [It has recently been claimed that at still higher temperatures... 

The simple hydrides of the group-III metals have not been extensively studied with respect to their ability to reduce boron compounds to diborane, but Adams (2) refers to cin industrial report which records that aliominum hydride is effective. It thus converts triphenyl borate to diborane (182), and its dialkoxy derivatives of formula AlH(0R)2 are also known to reduce the boron halides to the same compound (156). 

Unlike boron, the development of heavier Group 13 congener complexes with carbenes has been sluggish. Like boron, however, early examples of carbene complexes with Al, Ga, and In were simple Lewis adducts of the carbene with ER3 species (E = Al, Ga, or In R = alkyl, aryl, halide, or hydride). Recently, Aldridge explored the coordination chemistry of NHC-EHj adducts (104, E = Al or Ga) with [M(CO)4(COD)] (M = Cr, Mo), and was able to prepare the first examples of o-gallane complexes (105, Seheme 5.18). ... 

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