Structure and metal binding of a 1H-1,5-benzodiazepine

The X-ray crystal structure of 2,3-dihydro-2,2,4-trimethyl-1H-1,5-benzodiaz epine (L), which has medicinal effect on the central nervous system, has be en determined. The solid state conformation of the seven-membered heterocyc lic ring in L is found to be somewhat like an armchair. Its modes of bindin g to three metal ions - Ni2+, Cu2+ and Zn2+ - are identified. In cases of N i2+ and Cu2+, the seven-membered heterocyclic ring in L opens up following a hydrolysis of the imino bond promoted by these two metal ions. Zn2+ canno t effect such ring opening.