Treatment of N,N-bis-(pyridin-4-ylmeth-yl)cyclo-hexane-1,4-di-amine with hydro-chloric acid in ethanol led to the formation of the title salt, C18H26N42+·2Cl-·2H2O, which lies about a crystallographic inversion center at the center of the cyclo-hexyl ring. The asymmetric unit therefore comprises one half of the N,N-bis-(pyridin-4-ylmeth-yl)cyclo-hexane-1,4-di-ammonium dication, a chloride anion, and a solvent water mol-ecule. In the dication, the two trans-(4-pyridine)-CH2-NH2- moieties occupy equatorial sites at the 1- and 4-positions of the central cyclo-hexyl ring, which is in a chair conformation. The terminal pyridine ring is tilted by 27.98 (5)° with respect to the mean plane of the central cyclo-hexyl moiety (r.m.s. deviation = 0.2379 Å). In the crystal, dications, anions, and solvent water mol-ecules are connected via N/C/O-H⋯Cl and N-H⋯O hydrogen bonds together with C-H⋯π inter-actions, forming a three-dimensional network.
Keywords: condensation reaction.; crystal structure; diprotonated structure; dipyridyl salt; hydrogen bonding.