Lactams dicarboxylic acid amide

A number of complexes with ligands related to amides, lactams and antipyrine (2,3-dimethyl-l-phenylpyrazol-5-one), as well as complexes with dicarboxylic acid amides are also known (Table 36), but little structural information is available for them. The diantipyrylmethane complex, UI4-4L-2H20, is probably ionic, [UL4]I4-2H20. 

Table 36 Complexes of Actinide(IV) Compounds with Lactams, Antipyrine (2,3-Dimethyl-l-phenylpyrazol-5-one, ATP) and its Derivatives, and Dicarboxylic Acid Amides...

Lactams from dicarboxylic acid amide esters via dicarboxylic acid imides by decarbonylation... 

The manufacture of the large variety of polyamides (commonly referred to as nylons) occurs through polycondensation of amino carboxylic acids (or functional derivatives of them, e.g. lactams) and from diamines and dicarboxylic acids. Labeling the amino groups with A and the carboxyl groups with B allows differentiation of the different chemical structures between the two types AB (from amino carboxylic acids) and AA-BB (from diamines and dicarboxylic acids). The number of C atoms in the monomers acts as a code number for the identification of the polyamides. The polycaprolactam manufactured from caprolactam (type AB) is then called polyamide 6 (PA 6). The number of carbon atoms in the diamine is given first for type AA-BB followed by the number of atoms in the dicarboxylic acid, e.g. PA 66 for polyhexamethylenedia-dipic amide from hexamethylenediamine and adipic acid. For copolymers the components are separated by a slash, e.g. PA 66/6 (90 10) is a copolymer composed of 90 parts PA 66 and 10 parts PA 6. 

There are a number of other specialty polyamides produced from a combination of other diamines and dicarboxylic acids and/or lactams of varying number of carbon atoms. PA-11 and PA-12 with 11 and 12 methylene units between each repeat amide group are relatively low melting point (170°C), but exhibit excellent ductility and moisture resistance. 

Polyamides contain the amide group —NH—CO— and can be classified in two homologous series. In the Perlon series, monomeric and repeat units are identical, since these polyamides occur either by the polymerization of lactams (cyclic amides) or the polycondensation of co-amino carboxylic acids. In contrast, the polyamides in the Nylon series are formed by the poly condensation of diamines and dicarboxylic acids Thus, two monomeric units form one repeat unit. 

There are cyclic esters (known as lactones), cyclic amides (known as lactams), cyclic anhydrides, and cyclic imides. The structures for these derivatives are presented in Chapter 20, Section 20.6.5. The chemical reactions associated with derivatives of dicarboxylic acids are discussed in Chapter 20 as well. 

The second largest volume nylon is nylon 6. Nylon 6 is not made from a diamine and a dicarboxylic acid, but from a six carbon cyclic amide. Cyclic amides are called lactams and caprolactam is a six-carbon lactam. Caprolactam can be made by the reaction of cyclohexanone with hydroxylamine, followed by a Beckmann rearrangement. 

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