One-dimensional metal–organic coordination polymers make up a class of compounds with potential towards the development of practical, new magnetic materials. Herein, a rare example of an ABBABB coupled linear chain comprised of alternating dicopper(II) tetraacetate units bridged to copper(II) acetate monomer units via axial η2:η1:µ2 coordinated acetate is reported. Examination of the structure, determined by small molecule X-ray crystallography, shows that each Cu(II) ion is in a dx2–y2 magnetic ground state. Magnetic susceptibility and magnetization data were collected and, consistent with the structural interpretation, demonstrate that the Cu(II) dimer (paddlewheel) exhibits classic antiferromagnetic exchange, while the S = 1/2 Cu(II) monomer is uncompensated in the ground state (low temperature regime.) Data were therefore fitted to a modified Bleaney-Bowers model, and results were consistent with the only other reported chain in this class for which magnetic data are available.

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Structure and Magnetic Properties of a 1D Alternating Cu(II) Monomer―Paddlewheel Chain

The abnormal magnetic behaviour of the single crystal of Cu(CH3COO)2H2O is discussed in the light of its magnetic and fine structure studies. The large magnetic anisotropy and the sharp fall of its principal susceptibilities with the fall of temperature may be attributed to anisotropic negative exchange interaction between paramagnetic ions.

Magnetic properties of copper acetate at low temperatures

The magnetic behaviour of a cupric acetate monohydrate single crystal is discussed. Results reported by various workers are discussed in the light of crystal structure and Bleaney and Bowers theory. It is suggested that Guha's magnetic data are erroneous, and that his suggestion of anisotropic exchange interaction is unnecessary. Bleaney and Bowers theory is shown to give good agreement with experimental results with a constant value of exchange integral and without including anisotropic exchange term in the Hamiltonian.

S. C. Mathur

Papers

Magnetic properties of copper acetate at low temperatures