Synthesis and characterization of a new family of bi-, tri-, tetra-, and pentanuclear ferric complexes

Abstract

Nine members of a new family of polynuclear ferric complexes have been synthesized and characterized. The reaction of Fe(O2CMe)2 with polydentate Schiff base proligands (H2L) derived from salicylidene-2-ethanolamine, followed in some cases by reaction with carboxylic acids, has afforded new complexes of general formulas [Fe2-(pic) 2(L)2] (where pic- is the anion of 2-picolinic acid), [Fe3(O2CMe)3(L)3], [Fe,(OR) 2(O2CMe)2(L),], and [Fe5O(OH)(O 2-CR)4(L)4]. The tri-, tetra-, and pentanuclear complexes all possess unusual structures and novel core topologies. Mössbauer spectroscopy confirms the presence of high-spin ferric centers in the tri- and pentanuclear complexes. Variable-temperature mag..