Synthesis and resolution of 1,11-diamino-dibenzo[d,f][1,3]dioxepine: A route to new asymmetric ligands and their complexes

Reaction of 2-iodo-3-nitrophenol with methylene iodide and Ullmann intramolecular coupling of the produced 1,1′-[methylenebis(oxy)]bis[2-iodo-3-nitro]benzene afforded 1,11-dinitro-dibenzo[d,f] [1,3]dioxepine, characterized by single crystal X-ray analysis. The title diamine was obtained by reduction of the nitroderivate with hydrazine hydrate. Resolution of the enantiomers of the novel C2-symmetric ligand can be easily obtained by use of tartaric acid. A test on the coordinating ability of the diamine has produced a complex examined by X-ray diffraction analysis.