Base-stabilized silanone molybdenum complexes were synthesized by the oxygenation of the M=Si bond in the silyl(silylene)molybdenum complex with 1 eq. of PNO in the presence of Lewis base L. The PNO-coordinated silanone complex (L = PNO) was converted to cis-[Cp*(OC)2Mo{OSiMes2(OSiMe3)}(PMe3)] in the presence of excess PMe3.