Pd(II) and Ni(II) complexes containing ONNO tetradentate Schiff base ligand: Synthesis, crystal structure, spectral characterization, theoretical studies, and use of PdL as an efficient homogeneous catalyst for Suzuki-Miyaura cross-coupling reaction

Two new palladium(II) and nickel(II) Schiff base complexes are prepared through the reaction of Pd(OAc)(2) and Ni(OAc)(2)center dot 4H(2)O with a tetradentate ONNO Schiff base, derived by condensing 4,5-dimethyl-1,2-phenylenediamine and 4-methoxysalicylaldehyde. The elemental analysis (CHN) and other spectroscopic techniques such as FT-IR and H-1 NMR were used to characterize the synthesized ligand and its corresponding metal complexes. Moreover, the crystal structure of the Pd(II) complex was investigated by the single crystal X-ray diffraction analysis. The diffraction analysis explores a slightly distorted square planar geometry of the PdL complex due to the coordination with deprotonated phenolic O-atoms and N-atoms from azomethine chromophore. The DFT-based theoretical calculations which employed the B3LYP/Def2-TZVP level of theory explore that the theoretical results corresponded to the actual data obtained via spectroscopic characterization.