Synthesis and structure characterization of boron complexes containing C2-symmetric tertiary amine ligands: Assessment catalytic degradation of dyes and antioxidant properties

Abstract

In this study, a new and simple method for synthesizing boron complexes was presented. The boron complexes with C₂-symmetric ligands were prepared from in situ generated tertiary amine by the reaction of salicylaldehyde with primary amine in the presence of sodium borohydride. The boron complexes were characterized by ¹H and ¹³C NMR spectroscopy, elemental analysis, and mass spectrometry. The crystal structures of complexes 1 and 2 were determined by single crystal X-ray diffraction method. The complex is a mononuclear boron complex with a tertiary amine ligand. The boron center is tetracoordinated with a distorted tetrahedral geometry. Catalytic activities of the boron complexes in the reduction of dyes, was investigated using sodium borohydride as a reducing agent. Complexes 1 and 2 were effective catalysts for degradation of dyes. Kinetic studies reveal that the reduction of methylene blue is of the first order. Free radical scavenging activities of the boron complexes have been tested using DPPH, ABTS and hydroxyl radicals, respectively. The result shows that the boron complexes have effective antioxidant activity.