In this thesis, phosphonium salts (I),(II) have been synthesized through the formation of (1,3-dichloro propanon) with pph 3 ,followed by the reaction of Pd(OAc) 2 and the mononuclear complex [Pd(CHPPh 3 ) 2 COCl] and dinuclear complex [Pd(CO)(CH)PPh 3 (CH 2 )(M-Cl)(OAc)] 2 have been produced. The reaction of mononuclear complexes and bidentate ligands [L=phen(phenanthroline)، 4-mepy،dppe(bis(diphenylphosphino ethane) giving the mononuclear complexes [Pd(X)(CHPPh 3 ) 2 CO][TfO] 2 (X=phen,4-mepy,dppe) and the reaction of dinuclear palladium complexes and bidentate ligands [L=phen(phenanthroline), 4-mephen(4-methyl phenanthroline)، 5-NO 2 phen(5-NO 2 phenanthroline),bipy(2،2'-bipyridine)] giving the mononuclear complexes [Pd(X)(CH 2 )(CH)(PPh 3 )COCl]TfO (X=phen،4-mephen، 5-NO 2 phen،bipy) the complexes were characterized by FT-IR، 1 H-NMR, 13 C-NMR, Termogravimetry and X-ray diffraction study of [Pd(phen)(CH 2 )(CH)(PPh 3 )COCl]TfO، [Pd(4-mephen)(CH 2 )(CH)(PPh 3 )COCl]TfO.The IR spectra of phosphonium salts show a absorption in the 1734cm-1. The frequence CO bond which is sensitive to complexation occurs from 1500cm-1 in the ylide. This band appear at lower energies compared to that found in the phosphonium salts،due to the charge delocalization present in such compound .coordination of ylide through the carbon atom causes an increase in the frequency band whereas for O-coordination a lowering of the frequency band is expand. The 1 H-NMR signals for the PCH group of complexes are shifted downfiled compared to that of the free ylides, as aconsequence of the inductive effect of the metal center. The reaction of dinnuclear palladium complex with bidentate ligands [L=phen،bipy، 4-mephen،5-NO 2 phen) to prepare orthopalladated complexes in the room temperature single crystals of [Pd(phen)(CH 2 )(CH)(PPh 3 )- COCl]TfO، [Pd(4-phen)(CH 2 )(CH)(PPh 3 )COCl]TfO، suitable for X-ray crystallography ، were obtained، which demonstrate the existence of the TfO as counter ion in the solution. The ORTEP diagram of the complexes demonstrate the orthopalladation occurring at the ph ring of the phosphine unit in endoposition.The palladium atoms of complexes are located in disorted square planer environments.The analysis termogravimetry shows that the orthopalladated complexes shows that it is fairly stable up to 300°C and then degradation start. The weight loss was observed in the temperature range of 300-500°C. In the second thesis ،the reaction of [CH 3 OCO-CH=PPh 3 ] and mononuclear palladium complex giving the orthopalladated complex [C 6 H 4 CH 2 NH 2 Pd{O-COCH 3 CHPPh 3 }]TfO the complexes were characterized by FT-IR،NMR.The IR spectra of [CH 3 OCO-CH=PPh 3 ]show a absorption in the 1616cm -1 . The IR spectra of [C 6 H 4 CH 2 NH 2 Pd{O-COCH 3 CHPPh 3 }]TfO show absorption in the 1538cm -1 . The IR absorption band observed for these complexes show a lowering of frequency CO indicating coordination of the ylide oxygen for these complexes.The 31 P-NMR spectra shows a sharp signal resonance shifted slightly up-field relative to the free ylide and is again in agreement with O-coordination , because C-coordination would result in a down-field shiftThe 31 P-NMR spectra of palladium complexe [C 6 H 4 CH 2 NH 2 Pd{O.-COCH 3 CHPPh 3 }]TfO shows that it has transoid and cisoid isomers. The Transoid is more stable than Cisoid isomer.