Coordination compounds of carbonyl oxygen polychelate ligand; synthesis, physicochemical characterization and biological evaluation

Abstract

The work covers the formation of the bisaldehyde ligand 2,2'-[ethane-1,2diylbis(oxy)] dibenzaldehyde (M) and its metal complexes. The synthesis of M was achieved via two steps in which two equivalents of the salicylaldehyde were reacted with KOH in an ethanolic medium. Subsequently, the resulting compound dissolved in DMF and one equivalent of 1,2-dibromoethane was added. Adding an ethanolic solution of metal chloride of a range of metal ions to the ligand in a 1:1 (M:L) mole ratio resulted in preparing a new five monomeric complexes. The entity of the isolated structure for the prepared compounds was confirmed using physicochemical methods (FT-IR, electronic spectroscopy, mass and 1H, 13C-NMR spectra, elemental microanalysis, magnetic susceptibility and molar conductance). The characterization data indicated the isolation of six and four-coordinate monomeric complexes with the general formula; [Cr(M)(Cl)2(H2O)2]Cl, [M(M)(Cl)2].H2O (where M= Fe(II), Co(II) and Cu(II)) and [Ni(M)]Cl2.H2O. The anti-microbiological activity of the title compounds (ligand and complexes) was tested against various bacterial and fungal microorganisms. The acquired data revealed that the metal complexes became potentially more active than the M. Keywords: Bisaldehyde ligand; Novel monomeric metal complexes; Structural study; Antimicrobial activity.