Russian Chemical Bulletin, International Edition, Vol. 54, No. 3, pp. 600—605, March, 2005 600
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 592—596, March, 2005.
1066-5285/05/5403-0600 © 2005 Springer Science+Business Media, Inc.
Dinuclear copper(II) complexes with
an unsymmetrical exchange fragment
V. A. Kogan,
a
V. V. Lukov,
a
V. M. Novotortsev,
b
I. L. Eremenko,
b
and G. G. Aleksandrov
b
a
Rostov State University,
7 ul. Zorge, 344090 Rostov-on-Don, Russian Federation.
E-mail: kogan@chimfak.rsu.ru
b
N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
31 Leninsky prosp., 119991 Moscow, Russian Federation.
E-mail: ilerem@igic.ras.ru
New dinuclear copper(II) complexes with azomethines and hydrazones, which were pro-
duced by condensation of substituted salicylaldehyde derivatives with 1,3-diaminopropan-2-ol
or carbo(thiocarbo)hydrazide, were studied. The structures of the [Cu
2
L(μ-
CH
2
ClCOO)(CH
3
OH)]•(CH
3
OH) (L = C
17
H
15
N
2
O
3
) and [Cu
2
L
2
(Cl
3
CCO)(CH
3
OH)]•H
2
O
(L
2
= C
32
H
42
N
4
O
3
) complexes were established by X-ray diffraction. The magnetic properties
of these complexes, including the influence of the nature of the substituents in the ligands on
exchange interactions, were studied.
Key words: dinuclear complexes, copper(II), exchange interactions, unsymmetrical ex-
change fragment, magnetochemical correlations.
Dinuclear copper(II) compounds with azomethine
ligands and their analogs with other 3d atoms have at-
tracted particular attention because of their structural
characteristics and magnetic properties.
1—19
The Cu
II
atoms contain one unpaired electron, which substan-
tially simplifies calculations of the energy parameters
of exchange interactions. In addition, complexes with
the azomethine ligand contain the stable dinuclear
Cu(μ-X)(μ-X
1
)Cu fragment, whose geometric parameters
depend only slightly on the nature of the substituents at
the periphery of the molecule. This fact allows one to
rather correctly estimate the exchange parameters for se-
ries of complexes and predict the existence of new com-
pounds possessing the desired magnetic properties. In this
respect, compounds containing various types of X and X
1
bridges (for example, containing one- and three-atom
bridges) are of most interest. Among these compounds
are copper complexes, in which the carboxylate group
serves as one of the bridging ligands (structures A and B).
Investigations of such complexes containing various
substituents in chelate-bridging ligands and the carboxy-
late group provide estimates of the influence of the elec-
tronic and steric factors on the energetics of the spin-spin
exchange. However, it is important to know not only the
magnetic properties but also the detailed geometry of the
complexes, which requires the use of X-ray diffraction. In
the present study, we analyzed the magnetic data for a
series of compounds of types A and B and established the
structures of the key complexes.
Results and Discussion
Recently,
20,21
we have developed convenient proce-
dures for the synthesis of a series of complexes A and B.
The structure of the A-type copper complex (R
1
= R
2
= H,
R
3
= Me) has been established by X-ray diffraction analy-
sis.
21
Magnetic measurements and calculations of the ex-
change parameters (Table 1) revealed a wide range of the
–2J values for the systems under study. For complexes A,