Syntheses and structural characterisation of some heteroleptic aluminium(III) formamidinates

A range of heteroleptic aluminium(III) formamidinate/formamidine complexes have been prepared involving metathesis reactions between AlX3 (X = Cl, Br, I) and alkali metal formamidinates. The mononuclear, bis-substituted complexes of the composition [Al(XylForm)2Cl] (XylForm = N,N′-bis(2,6-dimethylphenyl)formamidinate) (1), [Al(XylForm)2I]·PhMe (2), [Al(DippForm)2Cl] (DippForm = N,N′-bis(2,6-diisopropylphenyl)formamidinate) (3), [Al(DippForm)2I] (4), mono-substituted complexes of [Al(DippForm)Cl2(thf)] (5), [Al(DippForm)ClBr(thf)] (6), [Al(XylFormH)Br3] (7) and [Al(DippFormH)Br3] (8) were synthesised. [Al3(XylForm)2(µ3-O)(OH)Cl4]2·PhMe (9), was isolated in the reaction between K(XylForm) and AlCl3 as a trinuclear compound.