Synthesis, spectral characterization, and X-ray crystal structure of Pd(II) complexes containing the orthometallated C,C-chelating ligand C6H4-PPh2C(H)C(O)CH2Cl

The ylide-phosphonium salt [PPh3CH2C(O)CH2Cl]+Cl− (1) reacted with Pd(OAc)2 to give the chloro-bridged dinuclear complex [Pd{C(H)PPh3C(O)CH2Cl}(μ-Cl)(OAc)]2 (2), which underwent bridge cleavage reactions with a neutral bidentate N-donor to afford the cationic orthometallated complexes [Pd{(C,C)-C6H4PPh2C(H)C(O)CH2Cl}(N−N)]CF3SO3 [N−N=bipy (2,2’-bipyridine) (3), phen (1,10-phenanthroline) (4), 4-Me-phen (4-methyl-1,10-phenanthroline) (5), and 5-NO2 phen (5-nitro-1,10-phenanthroline) (6)]. The complexes were identified and characterized by spectroscopic studies (IR and NMR). X-ray single-crystal analysis of 4 and 5 revealed the presence of an orthometallated C6H4-PPh2 unit and a C-linked ylide Pd−C(H). Thermal behavior of 3–6 is investigated by thermogravimetry.