Russian Chemical Bulletin, International Edition, Vol. 54, No. 9, pp. 2211—2214, September, 2005 2211
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2145—2148, September, 2005.
Brief Communications
1066-5285/05/5409-2211 © 2005 Springer Science+Business Media, Inc.
New antiferromagnetic tetranuclear pivalate complex
containing Fe
III
and Fe
II
atoms*
M. A. Kiskin,
a
A. A. Sidorov,
a
G. G. Aleksandrov,
a
Yu. G. Shvedenkov,
b
V. N. Ikorskii,
b
V. M. Novotortsev,
a
I. L. Eremenko,
a
and I. I. Moiseev
a
a
N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
31 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (495) 955 4835. E-mail: ilerem@igic.ras.ru
b
International Tomography Center, Siberian Branch of the Russian Academy of Sciences,
3a ul. Institutskaya, 630090 Novosibirsk, Russian Federation.
Fax: +7 (383) 33 1399. E-mail: schved@tomo.nsc.ru
The interaction of [K
2
Fe
III
4
(O)
2
(OOCCMe
3
)
10
(HOOCCMe
3
)
2
(H
2
O)
2
]
n
with 2-pyridine-
carboxaldehyde results in a mixed-valence complex Fe
II
Fe
III
3
(μ
3
-O)
2
(μ
2
-OOCCMe
3
)
7
L
2
•
•2.5MeCN•3H
2
O (L = 2-NC
5
H
4
COOH
0.75
K
0.25
). The structure of the complex was estab-
lished by X-ray analysis. The magnetic properties of the complex were studied.
Key words: iron complexes, X-ray diffraction study, 2-pyridinecarboxaldehyde.
Heterospin polynuclear coordination compounds are
of considerable interest in connection with search for
molecular magnetic systems in order to design new-gen-
eration electronic devices.
1,2
From this point of view,
iron derivatives appear to be convenient materials be-
cause they are readily available and cheap. Besides, a
distinctive feature of iron pivalate complexes is a high
solubility in organic solvents.
Heterospin polynuclear iron carboxylates are mainly
known in the form of triangular complexes containing
both Fe
III
(S = 5/2) and Fe
II
(S = 2) atoms in vari-
ous ratios.
3—7
Tetranuclear pivalate complexes with the
Fe
4
(μ
3
-O)
2
core comprised of two triangles sharing an
edge are only known for iron(III).
8,9
In this work we report on reduction of a tetranuclear
dianionic iron(III) oxopivalate complex with 2-pyridine-
carboxaldehyde resulting in a complex containing Fe
III
and Fe
II
atoms.
Results and Discussion
Recently,
9
we have shown that dissolution of a
polymeric complex [K
2
Fe
4
(O)
2
(OOCCMe
3
)
10
-
(HOOCCMe
3
)
2
(H
2
O)
2
]
n
(1) in MeCN affords the
[K(HOOCCMe
3
)(MeCN)]
2
[Fe
4
(O)
2
(OOCCMe
3
)
10
]
compound (2) containing discrete tetranuclear iron(III)
dianions (Scheme 1).
* Dedicated to Academician A. L. Buchachenko on the occa-
sion of his 70th birthday.