For 10 points, name this highly toxic metal whose hexavalent form is used as a strong oxidizing agent, with atomic number 24 and symbol Cr.
Franz Hein reacted a chloride of this non-iron element with phenylmagnesium bromide to synthesize its bis-benzene form, which was the first arene-containing sandwich compound. A chloride of this element is used in an alternative to the phosphorus-using Wittig reaction in order to create alkenes; that reaction is named for Takai. A mixture of pyridinium and another chloride of this element makes up the (*) Corey-Suggs reagent, which is an alternative to another compound containing this element named for Jones. For 10 points, name this highly toxic metal whose hexavalent form is used as a strong oxidizing agent, with atomic number 24 and symbol Cr.
Franz Hein reacted a chloride of this non-iron element with phenylmagnesium bromide to synthesize its bis-benzene form, which was the first arene-containing sandwich compound.
Chromium [accept Cr before mention]