Synthesis, structural characterization of complexes of Ni(II), Pd(II) with 5-bromo-6,7-dihiroxyl-1-methyl-3-sulfoquinoline by a combination of spectroscopy and density functional theory calculation

In this research, a new derivative of quinoline, namely 5-bromo-6,7-dihydroxyl-1-methyl-3-sulfoquinole (QOH) as well as two complexes of Ni(II) and Pd(II) with this ligand [M(QOH-1H)2] were synthesized. The molecular formulas and structures of the complexes were determined using a combination of IR, EDX, ESI MS and ''1H NMR spectra. Additionally, the structure of the palladium complex was assigned by a combination with quantum chemical calculations using the method of density functional theory which is implemented in Gaussian 09 program package. The results show that this is a square planar complex, in which the QOH ligand coordinates with the center ion Pd(II) via the O atom of its -OH phenol groups and the OH groups have trans configuration. Bond lengths and bond angles around the center metal were determined. (author)