Synthesis, electronic nature, and reactivity of selected silylene carbonyl complexes

Abstract

Room-temperature stable main group element carbonyl complexes are rare. Here we report on the synthesis of two such complexes, namely gallium-substituted silylene-carbonyl complexes [L(X)Ga]₂SiCO (X = I 2, Me 3; L = HC[C(Me)NDipp]₂, Dipp = 2,6-ⁱPr₂C₆H₃) by reaction of three equivalents of LGa with IDippSiI₄ (IDipp = 1,3-bis(2,6-ⁱPr₂C₆H₃)-imidazol-2-ylidene) or by salt elimination from [L(Br)Ga]₂SiCO with MeLi. Both silylene carbonyl complexes were spectroscopically characterized as well as with single crystal X-ray diffraction (sc-XRD), while their electronic nature and the specific influence of the Ga-substituents X was evaluated by quantum chemical computations. In addition, we report the oxidative addition reaction of [L(Br)Ga]₂SiCO with NH₃, yielding [L(Br)Ga]₂Si(H)NH₂4, demonstrating the promising potential of such complexes for small molecule activation.