The first carbene-stabilized silicon-catbon mixed oxide, (SiO2)(2)CO2 (4), was synthesized by CO2 oxidation of either carbene-stabilized disilicon, (L:Si=Si:L (L: = :C{N(2,6-(Pr2C6H3)-C-i)CH}(2)) (1), or carbene-stabilized Si2O3 (2) (which can be obtained via N2O oxidation of 1). The structure and bonding of 4 was probed by both experimental and computational methods.