Synthesis, characterization, crystal structure and DFT studies of a palladium(II) complex with an asymmetric Schiff base ligand

Abstract

A Pd(II) complex of tetradentate Schiff base ligand, bis(5-methoxysalicylidene)-4-methyl benzene-1,2-diamine (H2L) was prepared from Pd(OAc)2 in refluxing acetonitrile. The complex was characterized using FT-IR, lH NMR, 13C{1H} NMR spectroscopic techniques, elemental analyses (CHN). Also, its molecular structure was determined by single-crystal X-ray diffraction. The crystal structure data showed a tetradentate mode of coordination for Schiff base, through N2O2 donor sets. In addition, DFT calculations at M06-2X/Def2-TZVP level of theory were conducted to obtain electronic and structural properties of the studied species. NBO-CMO analysis combined with TD-DFT method was done to interpret electronic transitions by determining their included occupied and virtual orbitals. NBO-CMO data show that there are MMCT and LMCT in the studied complex. All theoretical data are in line with the experimental results.