4,7,13,16,21,24-Hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane hydrogen phosphate octahydrate: Synthesis and crystal structure

A crystalline hydrated salt of the 2.2.2-cryptand and phosphoric acid, [H₂(Crypt-222)](HPO₄) · 8H₂O (I), is synthesized. Its crystal structure is studied using X-ray diffraction analysis (space group P2₁/n, a = 9.244 Å, b = 25.750 Å, c = 13.218 Å, β = 95.87°, Z = 4; direct method, full-matrix least-squares method in the anisotropic approximation to R = 0.055 for 4622 reflections, CAD4 automated diffractometer, λMoK _α radiation). The structure contains the 2.2.2-cryptand dication with the rare exo-exo, conformation with two H atoms at two N atoms directed outside from the cavity. A P atom of the HPO ₄ ^2? anion has a considerably distorted tetrahedral coordination. The crystal of compound I contains a branched infinite three-dimensional system of intermolecular (interionic) hydrogen bonds.