New antimony-capped iron(II) and cobalt(III) clathrochelate precursors of the polytopic hybrid cage complexes: Synthesis, X-ray structures and electrochemistry

Abstract

Direct template macrocyclization of the three dimethylglyoxime molecules on the iron(II) ion and the capping of nonmacrocyclic K 3CoDm 3 tris-dimethylglyoximate with triethylantimony(V) derivatives led to the formation of triethylantimony-capped iron(II) and cobalt(III) clathrochelates. The complexes obtained have been characterized using elemental analysis, MALDI-TOF mass, IR, UV–Vis, 57Fe Mössbauer and 1H and 13C NMR spectroscopies, and X-ray crystallography. The influence of the nature of an encapsulated metal ion, the capping groups and the chelate fragments on a clathrochelate framework geometry is discussed. The cyclic voltammograms show oxidation and reduction waves assignable to Fe 2+/3+ and Co 2+/3+ couples of the encapsulated metal ion.