The compound is classified as a cyclic imide. Selective reduction of one of the imide carbonyl groups give the corresponding alcohol. Polyimide (sometimes abbreviated PI) is a polymer of imide monomers. The parent imide (NH) is an intermediate in nitrogen fixation by synthetic catalysts. It is the imide derivative of phthalic anhydride. The toughness of these materials reflects the rigidity of the imide functional group. This unsaturated imide is an important building block in organic synthesis. The name is a contraction of maleic acid and imide, the -C(O)NHC(O)- functional group. Heating the polygamic acid then results in cyclodehydration, forming the imide. A number of fungicides and herbicides contain the imide functionality. Lithium imide is an inorganic compound with the chemical formula . Protonated betaine bis(trifluoromethanesulfonyl) imide has been investigated as a solvent for uranium oxides. Usually, the acid chloride substrate reacts with the oxazolidinone to form an imide. Many high strength or electrically conductive polymers contain imide subunits, i.e., the polyimides. Likewise, imide can refer to a bisacylated amine "or" a twice deprotonated amine.