Trinuclear pyridyl functionalised hydroxylaminato complexes of aluminium, gallium and indium

摘要

The reaction of the donor functionalised N,N-bis[2-(pyrid-2-yl)ethyl] hydroxylamine [HON(C_2H_4-o-py)_2] and three equivalents of the Lewis-acids AlMe_3, GaMe_3 or InMe _3 resulted in the formation of dimethylhydroxylaminato-metal complexes of the general constitution [MMe_2ON(C_2H _4-o-py)_2·2MMe_3] with M = Al (1), Ga (2) or In (3) by methane elimination. An alternative method to generate complexes 1 and 2 is the transmetalation of [YCp_2ON(C_2H _4-o-py)_2] with an excess of AlMe_3 or GaMe _3, respectively. All compounds were characterised by elemental analysis, NMR spectroscopy and single-crystal X-ray diffraction. The complexes [GaMe_2ON(C_2H_4-o-py)_2· 2GaMe_3] (2) and [InMe_2ON(C_2H _4-o-py)_2·2InMe_3] (3) show highly dynamic behaviour in solution with the two pyridine nitrogen atoms changing their coordination to the metal atoms rapidly at ambient temperature. VT ~1H NMR experiments showed that this dynamic exchange can be frozen on the NMR time scale. In contrast to 2 and 3, complex 1 does not change its coordination mode at ambient temperature in non-coordinating solvents.