MOSSBAUER AND MAGNETIC STUDIES ON THE SPIN STATES OF DIIRON(III) PORPHYRIN DICOPPER(II) COMPLEXES

Authors
Citation
Sf. Huang et Hh. Wei, MOSSBAUER AND MAGNETIC STUDIES ON THE SPIN STATES OF DIIRON(III) PORPHYRIN DICOPPER(II) COMPLEXES, Hyperfine interactions, 91(1-4), 1994, pp. 809-814
Citations number
14
Categorie Soggetti
Physics, Atomic, Molecular & Chemical","Physics, Nuclear","Physics, Condensed Matter
Journal title
ISSN journal
03043843
Volume
91
Issue
1-4
Year of publication
1994
Pages
809 - 814
Database
ISI
SICI code
0304-3843(1994)91:1-4<809:MAMSOT>2.0.ZU;2-H
Abstract
Several biological model complexes of cytochrome c oxidase analogues, such as X(2)(TPP)(2)Fe-2(Apen)Cu2Cl4, where TPP = 5, 10, 15, 20-tetrap henylporphine, Apen = bis(acetylpyrazine)-ethylenediimine, X = Cl-, N- 3(-), Im, 1-Me-Im, 2-Me-Im, 4-Me-Im and OCH3-, were prepared. The elec tronic spin states of these complexes in solid state were studied by m eans of Mossbauer and EPR spectroscopies and magnetic susceptibility m easurements. The iron(III) atom of these complexes is present in diffe rent spin states, depending upon the nature of the axial ligand X of F e(III)-porphyrin; the N-3(-) Cl-, OCH3-, 2-Me-Im axial groups lead to complexes in a pure high-spin state independent of temperature. In con trast, the imidazole axial groups (e.g. Im, 4-Me-Im) behave differentl y and all show a temperature dependence of the (6)A(1) <----> T-2(2) s pin transition. The magnetic exchange behavior between Fe and Cu atoms in the present complexes is also discussed.