Plasticity of the coordination sphere of copper(II) complexes, its manifestation and causes

The electrochemical, photochemical and chemical control of the magnetic properties in molecular compounds is described. The preparation of various thin films of CrCr and FeFe Prussian blue on a conducting electrode allowed us to control the magnetic properties by varying the oxidation state of the component metals. The magnetic properties of CrCr Prussian blue show that the critical temperature and coercive field can be drastically modified by electrochemical treatment. That is, the compound, CrII1.29CrIII0.14[CrIII(CN)6] has ferrimagnetic properties with Tc (critical temperature) = 240 K and Hc (coercive field) = 25 G, while the reduced form, KCrII1.29CrIII0.14[CrII(CN)6], has Tc = 100 K and Hc = 220 G. Similarly, it was found that the critical temperature of FeFe Prussian blue shifts continuously from paramagnetic to magnetic with Tc = 12 K. These changes can be expressed as K4FeII4[FeII(CN)6]3 (paramagnetic) ←→ FeIII4[FeII(CN)6]3 (ferromagnetic, Tc = 4.5 K) + 4 K+ + 4e− and FeIII4[FeII(CN)6]3 (ferromag...

Control of the Magnetic and Optical Properties in Molecular Compounds by Electrochemical, Photochemical and Chemical Methods

J. C. Donini

Papers

Temperature-dependent tetragonal distortion in some thermochromic N,N-diethylethylenediamine complexes of copper(II)

Untersuchung der temperaturabhaengigen tetragonalen verzerrungen in thermochromen cu(ii)-komplexen (i) mit n,n-diaethylaethylendiamin