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Chromium(II)

Chromium(II) compounds are uncommon, in part because they readily oxidize to chromium(III) derivatives in air. Water-stable chromium(II) chloride CrCl that can be made by reducing chromium(III) chloride with zinc. The resulting bright blue solution created from dissolving chromium(II) chloride is stable at neutral pH. Some other notable chromium(II) compounds include chromium(II) oxide CrO, and chromium(II) sulfate CrSO. Many chromium(II) carboxylates are known. The red chromium(II) acetate (Cr (O CCH)) is somewhat famous. It features a Cr-Cr quadruple bond.