The crystal structure at STP of this metal is by far the most complex of all metallic elements, with 58 atoms per unit cell. A dark green liquid oxide of this metal explodes on contact with most organic compounds. Bleach oxidizes this metal from 3+ to 5+ in a reaction catalyzed by a complex of this metal with a salen ligand, the Jacobsen epoxidation. In one cluster, four atoms of this metal are successively oxidized through states S0 to S4 to then oxidize (*) water. This metal’s dioxide is the most common cathode for alkaline batteries. A brown precipitate of this metal’s (-5[1])dioxide in Baeyer’s test indicates the presence of alkenes or alkynes, which an oxyanion (-5[1])of this metal converts to diols. For 10 points, name this transition metal that has the 7+ oxidation state in an oxyanion that is a powerful oxidizer with a magenta color. ■END■ (10[2])