In this thesis, ortho metalated complexes have been synthesized. The ortho -palladated complexes [Pd(C 6 H 4 CH 2 NH(t-Bu)X] 2 can be prepared by refluxing equimolecular amounts of Pd(OAc) 2 and [C 6 H 5 CH 2 NH(t-Bu)] in benzene for 24 h in 50?c, followed by addition of NaX (X= Cl, Br) in MeOH in this stage of the reaction Br and Cl will be replaced with acetate bridge . The halogeno-bridges in dimeric ortho-palladated complexes containing secondary aryl-alkylamines are easily cleaved by various neutral ligands, including sym-Collidine, PPh 3 , to afford mononuclear metallacycles. In the second part the 1:2 insertion reaction have been done with Dimethylacethylenedicarboxylate in the room temperature also 1:4 insertion reaction have been done y refluxing Pd-C with Dimethylacethylenedicarboxylate In aceton and in 50?c . The complexes were chractrized by FT-IR, NMR, and X-ray diffraction study of [Pd(C 6 H 4 CH 2 NH(t-Bu)sym-Collidine(Br)].X-ray datas shows distortion square planar structure for this complexe. 15 protones of the PPh 3 group in the [Pd(C 6 H 4 CH 2 NH(t-Bu) PPh 3 (Cl)] have been detected clearly in 1H NMR, as two multiplied band that refers to 9 protones of meta and para in 7.4-7.52 ppm and 6 protones of orto groups in 7.59-7.64 ppm. 31P{1H} NMR of this complex show that this complex may have two isomer. In other part phosphorus ylide [NO 2 BdppeY] has been synthesized through the formation of phosphonium salt and dihydrogenation, followed by the reaction of Pd(OAc) 2 and the dinuclear complexes [Pd(?-R)(NO 2 BdppeY)] 2 R= OAc, Cl, have been prepared. Then monomer complexes were prepared by using of 2:1 ratio of neutral ligands (PPh3, 2,4,6-tri methylprydine) and dinuclear complex in CH 2 Cl 2. The complexes were chracterized by FT-IR, NMR, UV-Vis and X-ray diffraction study of [NO 2 BdppeY]. The disappearance of peak in 2150 cm -1 in inserted complexes shows acethylene group in dimethylacethylene dicarboxylate converts to ethylene group in complex In The 1 H NMR of dimeric ortho palladated complexes the presence of one series of band on each spectrum can be originated from the presence of only trans isomer as a result of the ortho palladated of n-benzyl-tert-buthylamine The Single crystals of [Pd(Br)(Me 3 Py)(NH(t-Bu)CH 2 C 6 H 4 ] suitable for X-ray crystallography, were obtained. Although the ortho palladated complex remarkably warped, the environment around the Pd is planar. 1 H NMR of the [PdNH(t-Bu)CH 2 C 6 H 4 (Cl)(PPh 3 )] and [Pd(Br)(Me 3 Py)(NH(t-Bu)CH 2 C 6 H 4 ] proves the Anisotropy effect of triphenylphosphin and 2,4,6-trimethylprydine rings on H6 of these complexes and have been shifted to lower field or the shielding. In the 31 P-{ 1 H} NMR spectra of all ylide complexes, the presence of two isomer of C,P coordination (major isomer) and P,O coordination(minor isomer), have been confirmed. The FT-IR spectra of all complexes show a strong absorption in the range of 1582-1621 cm -1 , which have been shifted to higher frequency with respect to the parent ylid, meaning that the ylid is C-bonded to the palladium center that refers to major isomer C,P coordination. The X-ray crystallography of [NO 2 BdppeY] shows that the terminal group of PPh 2 has converted to O=PPh 2 . consequently in the 31 P-{ 1 H} NMR of the some complexes, the C,P coordination products with O=PPh 2 group have been seen.