Two oxazane macrocycles.

The 20-membered ring in 1,7,11,17-tetraoxa-2,6,12,16-tetraazacycloeicosane tetrahydrochloride, C(12)H(32)N(4)O(4)(4+).4Cl(-), adopts an endo conformation, while the 18-membered ring in 1,6,10,15-tetraoxa-2,5,11,14-tetraazacyclooctadecane tetrahydrochloride, C(10)H(28)N(4)O(4)(4+).4Cl(-), lies about an inversion centre and adopts a symmetrical conformation. In the crystal structures of both compounds, the cations and chloride anions are linked by N-H...Cl hydrogen bonds into planar sheets of molecules; the sheets are linked into three-dimensional networks via C-H...Cl hydrogen bonds.