| Abstract
| - The reactions of the anionic gallium(I) N-heterocyclic carbene (NHC) analogue, [K(tmeda)][:Ga{[N(Ar)C(H)]2}], Ar= C6H3Pri2-2,6, with the heavier group 14 alkene analogues, R2EER2, E = Ge or Sn, R = −CH(SiMe3)2, havebeen carried out. In 2:1 stoichiometries, these lead to the ionic [K(tmeda)][R2EGa{[N(Ar)C(H)]2}] complexes whichexhibit long E−Ga bonds. The nature of these bonds has been probed by DFT calculations, and the complexeshave been compared to neutral NHC adducts of group 14 dialkyls. The 4:1 reaction of [K(tmeda)][:Ga{[N(Ar)C(H)]2}] with R2SnSnR2 leads to the digallyl stannate complex, [K(tmeda)][RSn[Ga{[N(Ar)C(H)]2}]2], presumablyvia elimination of KR. In contrast, the reaction of the gallium heterocycle with PbR2 affords the digallane(4), [Ga{[N(Ar)C(H)]2}]2, via an oxidative coupling reaction. For sake of comparison, the reactions of [K(tmeda)][:Ga{[N(Ar)C(H)]2}] with Ar‘2EEAr‘2, E = Ge, Sn or Pb, Ar‘ = C6H2Pri3-2,4,6, were carried out and led to either noreaction (E = Ge), the formation of [K(tmeda)][Ar‘2SnGa{[N(Ar)C(H)]2}] (E = Sn), or the gallium(III) heterocycle,[Ar‘Ga{[N(Ar)C(H)]2}] (E = Pb). Salt elimination reactions between [K(tmeda)][:Ga{[N(Ar)C(H)]2}] and the guanidinatogroup 14 complexes [(Giso)ECl], E = Ge or Sn, Giso = [Pri2NC{N(Ar)}2]-, gave the neutral [(Giso)EGa{[N(Ar)C(H)]2}] complexes. All complexes have been characterized by NMR spectroscopy and X-ray crystallographic studies.
- The reactions of the anionic gallium(I) N-heterocyclic carbene (NHC) analogue, [K(tmeda)][:Ga{[N(Ar)C(H)]2}], Ar = C6H3Pri2-2,6, with the group 14 alkene analogues, R2EER2, E = Ge or Sn, R = −CH(SiMe3)2, have been carried out. These afforded ionic complexes, [K(tmeda)][R2EGa{[N(Ar)C(H)]2}], which exhibit long E−Ga bonds. The nature of these bonds has been probed by DFT calculations, and the complexes have been compared to neutral NHC adducts of group 14 dialkyls. A variety of other complexes of the gallium heterocycle with group 14 element(II) fragments have been prepared, which include the neutral guanidinato germanium and tin complexes, [(Giso)EGa{[N(Ar)C(H)]2}], E = Ge or Sn, Giso = [Pri2NC{N(Ar)}2]- (see picture). As part of this study, the first structurally characterized Sn−Ga bonds in molecular compounds are reported.
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