Abstract :
The novel dinuclear complex [Co2(pyrazine)(fumarato)2(H2O)8]·7H2O which contains the mixed N- and O-donor ligands has been
prepared and structurally characterized. The structure is made up of the symmetrical pyrazine-bridged [Co2(pyrazine)(fumarato)2(H2O)8]
moiety and 7 lattice water molecules. The X-ray analysis reveals that it is the first dinuclear complex in which the fumarato dianion acts as a
unidentate ligand instead of a bridge. An extended two-dimensional structure was formed through hydrogen bonds. Magnetic susceptibility
measurements reveal that a very weak antiferromagnetic interaction exists between the high-spin Co(II) ions within the binuclear unit with
J ¼ 20:16 cm21 based on the spin Hamiltonian H ¼ 22JS1S2:
q 2004 Elsevier B.V. All rights reserved.
Keywords :
Synthesis , including theazide-bridged , Two-dimensional extended structure , Cobalt(II) complex , oxamidato-bridged , Magnetic properties1. IntroductionOver the past decades , extended systems of a variety ofmetals and ligands have been characterized providing veryinteresting information about magneto-structural corelationsin these compounds. Our interests are mainlyfocused on the molecular-based magnets , cyanide-bridged , the design of polynuclear metalcomplexes has been an active area of research incoordination chemistry. The polynuclear complexes notonly provide the opportunity for the study of magneticexchange mechanisms involving several metal ions , thiocyanato-bridged , Novel dinuclear complex , carboxylate-
