Aluminium trihalide complexes

Three main structural sub-groups can be recognised alkylaluminium dihalides, dialkylaluminium halides, and trialkyldialuminium trihalides (equimolar complexes of a trialkylaluminium and an aluminium trihalide). While this is generally a very reactive group of compounds, similar in reactivity to trialkylaluminium compounds, increase in size of the alkyl groups present and in the degree of halogen substitution tends to reduce pyrophoricity. 

In the case of 87e and 87f insertion of a second equivalent of phosphinidene complex [(CO)5W-PCH(TMS)2] into a P-C or P-P bond of the three-membered ring has led to l,2-dihydro-l,2,3 triphosphete complexes lOOe and lOOf. The reactions of aluminium trihalides and gallium trichloride with 3 equiv of kinetically stabilized phosphaalkynes P CR proceed according to an unusual spirocyclotrimerization to provide the complexes 103a-103f exhibiting structural features of a zwitterionic diphosphirenium alkanide complex (Scheme 37). 

The simple addition complexes of the aluminium trihalides are formally analogous to those of the boron trihalides. Phosphine and phosphorus trihalides form addition compounds of the type X3P-ADC3, where X = H or halogen and X = halogen (9.129). 

The well-known Sm ry -arene complexes are generally prepared by the reaction of arenes with rare-earth trihalides in the presence of aluminium halides. This reaction was also effective with samarium diiodide and was extended to thulium diiodide however, an attempt to react Tml2 with naphthalene in toluene in the presence of aluminium trichloride was not successful but resulted in the isolation of an ry -toluene complex of Tm [77 -(CH3C6H5)Tm(AlCl4)3] (Figure 6) (Fagin et al., 2005). 

Complexes from the trihalides of aluminium and gallium with thiols, hydrogen sulphide and selenols, G.G. Hoffmann, Chem.Ber.. 1985, 118. 3320. 

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