Organogallium-oxygen compounds

Many organogallium-oxygen compounds are associated, self-assembled supermolecules. Their structure and chemistry have been reviewed [177-179]. 

Dimethylgallium hydroxide has been reported to be a trimer [Mc2GaOH]3, 71, on the basis of molecular-weight determinations in solution [180], but was found to be a tetramer, 72, by X-ray diffraction in the solid state, with Ga-O 1.94-1.99 A [181]. A trimer [Bu 2GaOH]3 has, however, been characterized and contains a planar Ga303 ring (Ga-O 1.957 A) [182-184], 

The sum of the covalent radii for the Ga-O pair is 1.909 A, which compares well with the value found in monomeric Bu 2GaOPh3 (1.831 A) [188] and Bu 2GaOC6H2Bu 3-2,4,6 [189], which contain a normal covalent Ga-O bond, but is considerably shorter than the dative Ga-O bonds. 

Cage molecules formed by self-assembly include structurally characterized orga- 

Monoorganogallium derivatives form more complex supramolecular aggregates, e.g. [MeGa03PBu ]4 and Li4[(MeGa)6(//3-0)2(Bu P03)6]-4THF [201]. 

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