Synthesis and structure of clozapine N-oxide hemi(hydrochloride): an infinite hydrogen-bonded poly[n]catenane

Abstract

The structure of the title compound, 2C18H19ClN4O•HCl or (CNO)2•HCl (C36H39Cl3N8O2), at 100 K has tetragonal (I4/m) symmetry. The dihedral angle between the benzene rings of the fused ring system of the CNO molecule is 40.08 (6)◦ and the equivalent angle between the seven-membered ring and its pendant N-oxide ring is 31.14 (7)◦. The structure contains a very strong, symmetrical O-H• • •O hydrogen bond [O• • •O = 2.434 (2) Å] between two equivalent R3N+-O- moieties, which share a proton lying on a crystallographic twofold rotation axis. These units then form a (CNO)4•(HCl)2 ring by way of two equivalent N-H• • •Cl hydrogen bonds (Cl- site symmetry m). These rings are catenated into infinite ..