New Schiff Bases Containing Silicon and Their Co(II) and Cu(II) Complexes: Synthesis, Complexation, Characterization, and Antimicrobial and Electrochemical Properties

Two novel Schiff base ligands, 4-((3-(trimethoxysilyl) propylimino) methyl) benzene-1,2,3-triol ((LH)-H-1) and 4-((3-(triethoxysilyl) propylimino) methyl) benzene-1,2,3-triol ((LH)-H-2), have been synthesized by the reaction of 2,3,4-trihydroxybenzaldehyde with 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane, respectively. The mononuclear Co-II and Cu-II complexes of these Schiff bases were prepared. The complexes of the Schiff bases are formed by coordination of N, O atoms of the ligands. The proposed structures were confirmed by elemental analyses, FT-IR, and UV-visible spectroscopy, magnetic susceptibility, and conductance measurements; the H-1 NMR spectra of the ligands were also recorded. The analytical data show that the metal to ligand ratio in the complexes containing silicon is 1:2. The electrochemical properties of the complexes have been investigated at 100 mVs(-1) scan rate in DMSO. In addition, the antimicrobial activity of (LH)-H-1 and (LH)-H-2 Schiff ligands, and their [M(L-1)2] and [M(L-2)2] type coordination compounds, were investigated.