Novel and Disparate Hydrogen-Bonding Associations in 13-Amino-6-hydroxy-13-methyl-1,4,8,11-tetraazacyclotetradecane Tetrahydrochloride Monohydrate

The title compound crystallizes in the monoclinic space group Pn with two independent [ LH4] Cl-4 . H2O formula units ( L = 13- amino- 6- hydroxy- 13- methyl- 1,4,8,11- tetraazacyclotetradecane) in the asymmetric unit. Despite pseudosymmetry, these two units exhibit subtle and interesting differences in their hydrogen- bonded association by the interchange of the water molecule site with one of the chloride anions. Although a pentamine, L crystallizes as a tetrahydrochloride in which the tetracation has a conformation similar to that of tetraprotonated cyclam ( 1,4,8,11-tetraazacyclotetradecane), despite a different pattern of protonation sites. Difficulties in purification are perpetuated in the crystal, the minor isomeric component co- crystallizing in one of the cation sites.