Disordered crystal structure of 1,10-diazonia-18-crown-6 sulfate dihydrate

A crystal structure of 1.10-diazonia-18-crown-6 sulfate dihydrate (I) was studied by x-ray diffraction method: [H2DA18K6]2+·SO2-4·2H2O; sp.gr. P1-bar, a=9.904(2), b=10.588(3), and c=10.819(4) A; α=67.61(2) deg., β=74.69(2) deg., and γ=64.94(2) deg.; and Z=2, R=0.049 for 2045 nonequivalent reflections with I≥3σ. The SO2-4anion in structure I is disordered--O atoms have two different orientations. The asymmetric unit contains two centrosymmetric crown dications DA18C6 with different molecular-ionic environment and different conformations. One of the crown dications has a conformation of the approximate symmetry D3d, and the other dication has an extended conformation corresponding to the minimum energy for the 18-crown-6 cyclic ether. There is a branched three-dimensional network of hydrogen bonds in the crystal structure of I