Donor-acceptor stabilized silaformyl chloride

Formyl chloride (H(Cl)C=O) is unstable at room temperature and decomposes to HCl and CO. Silicon analogue of formyl chloride, silaformyl chloride IPr center dot SiH(Cl)=O center dot B(C6F5)(3) (3) (IPr = 1,3-bis(2,6-diisopropyl-phenyl)imidazol-2-ylidene), was stabilized by Lewis donor-acceptor ligands. Compound 3 is not only the first stable acyclic silacarbonyl compound but also the first silacarbonyl halide reported so far.