Crystal structure and magnetic properties of two metal-picolinate systems obtained from degradation of bis(2-pyridylketone) through reaction with Mn(II) and Cu(II)
Mg. Barandika et al., Crystal structure and magnetic properties of two metal-picolinate systems obtained from degradation of bis(2-pyridylketone) through reaction with Mn(II) and Cu(II), POLYHEDRON, 18(8-9), 1999, pp. 1311-1316
The bis(2-pyridyl-ketone) compound is expected to have great potential as a
multidentate ligand with transition metals. However, similar ketone-contai
ning compounds, bis(2-pyridyl-ketone) could undergo metal-promoted hydratio
n. With the aim of determining its behaviour, bis(2-pyridyl-ketone) was rea
cted with Cu(II) and Mn(II). X-ray characterisation of the products reveals
the formation of complexes containing picolinate anions as products of the
degradation of bis(2-pyridyl-ketone). ESR spectroscopy for the compound wi
th Mn(II) (1) indicates an important zero-field splitting term originating
from the strong distortion of the resulting Mn(II) octahedra. The ESR spect
ra for the compound with Cu(II) (2) are consistent with the elongated Cu(II
)-octahedra. These octahedra form a monodimensional arrangement which shows
the occurrence of antiferromagnetic exchange couplings. (C) 1999 Elsevier
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