Magnetic properties higher oxides

Although stable at room temperatures, hohnium will corrode at higher temperatures and humidity. Its oxide coating is a yellowish film that reacts slowly with water and dissolves in weak acids. Holmium has one of the highest magnetic properties of any substance, but it has little commercial use. 

Many of these complexes are deeply colored and their electronic spectra contain very strong intervalence transfer bands in the visible, due to electron transfer from B to A (Robin and Day, 1967). They also show magnetic coupling and they have semiconducting properties. They are stable in air and in acid solutions, but they dissociate in alkali. They can be reversibly oxidized, whereby B gives up an electron and goes to a higher oxidation state, and the intense color disappears. 

Consistent with the extensive Fe-N 7r bonding, the equivalence of the two irons, the nonintegral oxidation state higher than Fe(III) and the unusual magnetic properties, (TPPFe)2N appears to be a good example of extensive delocalization between a pair of bridged metal ions. 

The first transition series or 3d-orbital series has a weak metallic character and less of atendancy for covalent bonding. This series also has strong oxidizing properties when in higher oxidation states. It forms many compounds with unpaired electrons, making it useful for catalysis and as magnetic materials. 

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