The ortho-metalated complex [Pd (µ-Cl) {C, C-[C 6 H 4 (PPh 2 CHC (O) C 6 H 4 -Ph-4) 2 }]}. ( 2 ) can be prepared by refluxing equimolecular amounts of Pd (OAc) 2 and {(Ph) 3 PCHCOC 6 H 4 -Ph-4}( 1 ) (PhY) in MeOH and CH 2 Cl 2 for 24 h, followed by addition of excess NaCl. Complex (2) reacts with 4-MePy to give the mononuclear derivative [PdCl{PhC 6 H 4 COCHPPh 2 C 6 H 4 }4-MePy}] ( 5 ) whose crystal structure has been determined by X-ray diffraction. The precursor of [Pd (µ-Cl) {C, C-[C 6 H 4 (PPh 2 CHC (O) C 6 H 4 Ph-4) 2 }]} ( 2 ), could not be isolated in a pure form, but it can be used as the starting material for the synthesis of derivatives of mono nuclear cyclo-palladated complexes. The C, C- metalated chelate is very stable, as shown by the reactions of ( 2) with PPh 3 , 3-MePy, 4-MePy and 2, 4, 6-Me 3 Py. Orthometallation and ylide C-coordination in complexes (3-6) are characterized with elemental analysis as well as various spectroscopic techniques.The reactions of the title ylides with HgX 2 (X =Cl, Br, I) in equimolar ratios using dry MeOH as solvent, have yielded [{Hg 2 (Cl) 4 (PhY) 2 ]( 7 ), [{Hg 2 (Br) 4 (PhY) 2 ]( 8 ), and [{Hg 2 (I) 4 (PhY) 2 ]( 9 ) and respectively. The reactions of the title ylides with AgTfO and AgBF 4 in molar ratios (2:1) using dry MeOH as solvent have yielded [Ag(PhY) 2 ]TfO ( 10 ) and [Ag(PhY) 2 ]BF 4 ( 11 ). The analytical data, IR and 1 H and 31 P{- 1 H}NMR data of the products were obtained.