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

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](2)SiCO (X = I 2, Me 3; L = HC[C(Me)NDipp](2), Dipp = 2,6-(Pr2C6H3)-Pr-i) by reaction of three equivalents of LGa with IDippSiI(4) (IDipp = 1,3-bis(2,6-(Pr2C6H3)-Pr-i)-imidazol-2-ylidene) or by salt elimination from [L(Br)Ga](2)SiCO 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](2)SiCO with NH3, yielding [L(Br)Ga](2)Si(H)NH2 4, demonstrating the promising potential of such complexes for small molecule activation.