Silicon-oxygen double bonds: a stable silanone with a trigonal-planar coordinated silicon center.

SiO in a complex: The first silanone that is stable at room temperature (3) is reported. The two-step synthesis involves carbonylation of the silylidyne complex 1 to give the chromiosilylene 2, followed by oxidation of 2 with N2 O. Silanone 3 features a polar, short SiO bond (1.526(3) Å) to a trigonal-planar-coordinated silicon center and reacts with water to give the dihydroxysilyl complex.