Jm. Rueff et al., Structure and magnetism of a polycrystalline transition metal soap - Co-II[OOC(CH2)(10)COO](H2O)(2), EUR J INORG, (11), 2001, pp. 2843-2848
Diaquacobalt(II) n-dodecane-alpha,omega -dioate (2) has been synthesized by
metathesis of the corresponding potassium soap I and has been fully charac
terized by chemical and spectroscopic analysis. The crystal structure of 2
has been established by X-ray powder diffraction techniques combined with e
lectron diffraction experiments, It crystallizes in a monoclinic cell [P2(1
)/a; a = 9.6558(8), b = 7,4793(6), c = 19.8936(2) Angstrom, beta = 95.648(9
)degrees, V = 1429.7(3) Angstrom (3); Z = 2] and consists of stacked layers
of cobalt(II) ions connected by carboxylato bridges, thus forming chains t
hat extend along the a axis. These layers are separated by alkyl chains arr
anged quasi-perpendicularly to the polar sheets. Structure analysis reveals
a rare anti-anti conformation of the Co-OCO-Co fragments, which is thought
to be responsible for the weak antiferromagnetism of the Co-II chains. The
exchange coupling constant between the magnetic centres has been estimated
as J = -2.08 K.