In the bidentate ligand ethylene diamine forms a chelate complex with the copper ion. GABA can also be synthesized from putrescine by diamine oxidase and aldehyde dehydrogenase. Reaction of the anhydride with the diamine produces an intermediate amic acid. A diamine is an amine with exactly two amino groups. This aromatic diamine is an important precursor to many heterocyclic compounds. N-methyltransferase and oxidative deamination via diamine oxidase. For this purpose, samarium-153 is chelated with ethylene diamine tetramethylene phosphonate (EDTMP) and injected intravenously. Detoxification of Cadmium (Cd) with EDTA (Ethylene Diamine TetraAcetate) and other chelators is possible. Zinc and hydrochloric acid decompose it with formation of orthoxylylene diamine. The rings are susceptible to hydrolysis back to the diamine and the aldehyde. Its chemical properties resemble those for ethylene diamine, and it has similar uses. PPTA is a product of "p"-phenylene diamine (PPD) and terephthaloyl dichloride (TDC or TCl). P"p"PTA is a product of "p"-phenylene diamine (PPD) and terephthaloyl dichloride (TDC). Cadaverine is a toxic diamine with the formula NH(CH)NH, which is similar to putrescine's NH(CH)NH. An example (although not derived from a diamine) is hexamethylenetetramine derived from ammonia and formaldehyde.