Syntheses, structural studies and solution properties of iron complexes of some amide-substituted calixarenes

摘要

Iron(III) complexes of 5,11,17,23-tetra-tert-butyl-24-hydroxy-26,27,28-tris(diethylcarbamoylmetho xy) calix[4] arene (II) and 5,11,17,23,29,35-hexa-tert-butyl-36,39-dihydroxy-37,38,40,41-tetrakis(diet hylcarbamoylmethoxy) calix[6] arene (IV) have been synthesised, and a single crystal structure determination has been carried out on [Fe(II - H)] (FeCl4)(2); the iron in the complex cation is bound to all seven O atoms of the calixarene with the shortest Fe-O distance to the phenolate O atom. The voltammetric properties of these complexes and the previously described Fe(III) complex of 5,11,17,23-tetra-tert-butyl-25,27-dihydroxy-26,28-bis(diethylcarbamoylmeth oxy) calix[4] arene (I) have been studied. The results suggest that the complexes of I and II undergo a reduction which is metal-centred, and an oxidation which is ligand-centred. [References: 27]