From ferromagnets to high-spin molecules: the role of the organic ligands
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Ginsberg A. P., 1971, Inorg, Chim. Acta Rev., 5, 45
Morpugo G. O., 1980, Crystal structure and spectroscopic properties of a polynuclear complex between [bis(2-aminoethyl)amine]copper(II) and hexacyanoferrate(III), J. Chem. Soc. Dalton Trans., 111
Scuiller A., 1996, A rationale route to high spin molecules via hexacyanometallates: a new µ-cyano CrIIIMnII 6 heptanuclear complex with a low-lying S = 27/2 ground state, New J. Chem., 20, 1
P. Day (The Royal Institution London UK ). Has Professor Mallah made a cluster
containing a central ferrocyanide ion with six surrounding high-spin Fe(III)? Such
a species would mimic the local structure of Prussian blue for which we proposed
a mechanism to explain the ferromagnetic exchange between Fe(III) involving the
intervalence charge-transfer configuration many years ago (Mayoh & Day 1976).
T. Mallah. We have made a pentanuclear cluster containing a central ferrocyanide
with four surrounding high-spin Fe(III) chelated by a pentadentate ligand containing
two phenolato groups. The magnetic properties clearly show a ferromagnetic interac
tion between the high-spin Fe(III) ions through the diamagnetic low-spin Fe(II) as
observed in Prussian blue. A mechanism involving the intervalence charge transfer
configuration proposed by Mayoh & Day (1976) explains the ferromagnetic exchange
interaction. Unfortunately we were not able to observe the intervalence optical band
in our compound because of the presence of an intense band centred at 580 nm due
to the charge transfer between the phenolato groups and Fe(III).