Synthesis, structure and magnetic properties of an oxo-bridged dinuclear iron(III) complex [(TPyA)(FFeOFeF)-O-III-F-III(TPyA)](BF4)(2)center dot 0.5MeOH (TPyA = tris(2-pyridylmethyl)amine) containing the FFeIIIOFeIIIF linkage

摘要

The reaction of [Fe-II(H2O)(6)](BF4)(2) with tris(2-pyridylmethyl)amine (TPyA) and triethylamine in methanol under aerobic conditions forms [(TPyA)(FFeOFeF)-O-III-F-III(TPyA)](BF4)(2) center dot 0.5MeOH (1), in which each Fe(111) ion is coordinated to a TPyA and an F- ion as well as an oxo ion (O2-) linking two Fe(III) ions. I has offset face-to-face pi-pi interactions between the dimers, and possesses a supramolecular network structure. The magnetic susceptibility of 1 can be fit with g = 2.0, J/k(B) = - 153 K (106 cm(-1)), and theta = - 0.3 K [H = - 2JS(a) center dot S-b]. These indicate that very strong antiferromagnetic interactions occur via the oxo bridge within the Fe(Ill) dimer and weak antiferromagnetic interactions between the dimers. (C) 2006 Elsevier B.V. All rights reserved.