Cr in two oxidation states

The structure of Cr2p5, a compound of Cr(ii) and Cr(ni), has been described in Chapter 5. We note here some compounds which contain Cr(iii) and Cr(vi) or Cr(iv) and Cr(vi). 

The compounds M2Cr309 (M = Na, K, Rb) have been prepared under pressure as red crystals insoluble in water. The structure consists of rutile-type chains of Cr Og octahedra which are cross-linked by Cr 04 tetrahedra. 

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Group VIII and Other Transition Metals Compounds containing Cr in two oxidation states... 

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