Template Synthesis and Structural Characterization of Homo Binuclear Chromium(III), Manganese(III), Iron(III), Cobalt(III), and Ruthenium(III) Complexes with Octaazamacrocyclic Ligands


Abstract: The Schiff base octaazamacrocyclic ligands derived from primary diamines and 3,6-dimethyl/diphenyl-4,5-diazaocta-3,5-diene-2,7-dione, and their binuclear complexes [M_2LCl_4]Cl_2 [M = Cr(III), Fe(III), Co(III), or Ru(III)] and [Mn_2L(AcO)_4](AcO)_2 were synthesized by template condensation reactions. Attempts to synthesize the corresponding metal-free macrocyclic ligands did not prove successful. The overall geometry and stereochemistry of these complexes were elucidated by elemental analyses, magnetic susceptibilities, electronic spectra, infrared spectra, molar conductance measurements, ^1H NMR, and thermogravimetric analysis. All the trivalent metal ion complexes appear to be 1:2 electrolytes. An octahedral geometry is proposed for all the complexes.

Keywords: Synthesis, chromium, manganese, iron, cobalt, ruthenium, macrocycles

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