Coordination of a Si=O subunit to metals: complexes of donor-stabilized silanone featuring a terminal Si=O -> M coordination (M = Zn, Al)

The striking reactivity of donor-stabilised silanone LSi(DMAP)=O (1) [L = N(Ar)C(=CH(2))CH=C(Me)N(Ar), Ar = 2,6-iPr(2)C(6)H(3), DMAP = p-dimethylaminopyridine] toward Lewis acidic metal substrates Zn(OAc)(2), ZnMe(2), and AlMe(3) is reported. Two unprecedented addition products onto the Si=O double bond, [LSi(OAc)(mu-O)Zn(OAc)(DMAP)(2)] (2) and [LSi(OAc)(mu-O)](2)Zn(DMAP) (3), and two terminal complexes LSi(DMAP)=O -> ZnMe(2) (4) and LSi(DMAP)= O -> AlMe(3) (5) were obtained. Compounds 4 and 5 are unique, representing the first isolable and structurally characterised terminal Si=O -> Zn and Si=O -> Al complexes. All new compounds were fully characterised by (1)H, (13)C, and (29)Si NMR spectroscopy, EI-MS, elemental analysis and single-crystal X-ray diffraction analyses.