Syntheses, characterization, and crystal structures of cobalt(III) complexes derived from 2-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol with the antibacterial activity

Abstract

A mononuclear cobalt(III) complex [CoL(NCS)2(OH2)] (1) and a trinuclear cobalt(III—II—III) complex [Co{CoLN3(m1,1-N3)2(CH3OH)}2] (2), derived from the Schiff base ligand 2-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol (HL), are synthesized and characterized by IR and electronic spectra. The structures of both complexes are studied in detail by single crystal X-ray diffraction. In complex 1, the Co(III) atom is coordinated by three donor atoms of the Schiff base ligand, two thiocyanate N atoms, and one water O atom, forming an octahedral geometry. In complex 2, the terminal Co(III) atom is coordinated by three donor atoms of the Schiff base ligand, two end-on azide N atoms, and one terminal azide N atom, forming an octahedral geometry. The central Co(II) atom is coordinated by four end-on azide N atoms and two methanol O atoms, forming an octahedral geometry. The complexes exhibit interesting antibacterial activities against B. subtilis and E. coli.