Chelate conplexes of the type (CO) 4YnP% e2CH2CH2SiX2 I 8 (X= Me, Cl) have been prenared from Na [Mn (CO151 and Han (CO) 5, respectively, by two-steo reactions with the ligands Xe2PCH2CH2SlX2R' usinq alkali salt. amine or HC~ elimfnation.(CO), HnP~ e, CH, CH, SiCl~ is also obtained