Bidentate in the context of "Mu (letter)"

In chemistry, iron(III) or ferric refers to the element iron in its +3 oxidation state. Ferric chloride is an alternative name for iron(III) chloride (FeCl₃). The adjective ferrous is used instead for iron(II) salts, containing the cation Fe. The word ferric is derived from the Latin word ferrum, meaning "iron".

Although often abbreviated as Fe, that naked ion does not exist except under extreme conditions. Iron(III) centres are found in many compounds and coordination complexes, where Fe(III) is bonded to several ligands. A molecular ferric complex is the anion ferrioxalate, [Fe(C₂O₄)₃], with three bidentate oxalate ions surrounding the Fe core. Relative to lower oxidation states, ferric is less common in organoiron chemistry, but the ferrocenium cation [Fe(C₅H₅)₂] is well known.

Potassium ferrioxalate, also called potassium trisoxalatoferrate or potassium tris(oxalato)ferrate(III) is a chemical compound with the formula K₃[Fe(C₂O₄)₃]. It often occurs as the trihydrate K₃[Fe(C₂O₄)₃]·3H₂O. Both are crystalline compounds, lime green in colour.

The compound is a salt consisting of ferrioxalate anions, [Fe(C₂O₄)₃], and potassium cations K. The anion is a transition metal oxalate complex consisting of an iron atom in the +3 oxidation state and three bidentate oxalate C₂O2−4 ligands. Potassium is a counterion, balancing the −3 charge of the complex. In solution, the salt dissociates to give the ferrioxalate anion, [Fe(C₂O₄)₃], which appears fluorescent green in color. The salt is available in anhydrous form as well as a trihydrate.

Ferrioxalate or trisoxalatoferrate(III) is a trivalent anion with formula [Fe(C₂O₄)₃]. It is a transition metal complex consisting of an iron atom in the +3 oxidation state and three bidentate oxalate ions C₂O2−4 anions acting as ligands.

The ferrioxalate anion gives a lime green color to salts, and in solution it is fluorescent. The anion is sensitive to light and higher-energy electromagnetic radiation, which causes the decomposition of one oxalate to carbon dioxide (CO₂) and reduction of the iron(III) atom to iron(II). This property is exploited for actinometry.