Synthesis and crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis[dichloro(thiocyanato)copper(II)]

A new complex salt [4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis[dichloro(thiocyanato)copper(II)], [H₂(Crypt-222)][CuCl₂(SCN)]₂, is synthesized and studied by X-ray diffraction analysis. The crystals are monoclinic (space group C2/c, a = 14.603 Å, b = 8.330 Å, c = 25.091 Å, β = 100.76°, Z = 4). The structure is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.047 for 2943 independent reflections (CAD-4 automated diffractometer, λMoK _α radiation). The Cu²⁺ cations and Cl^? and SCN^? anions form infinite polymeric chains of spiro-conjugated alternating centrosymmetric four-membered CuCl₂Cu cycles and eight-membered Cu(SCN)₂Cu cycles through coordination bonds. The coordination polyhedron of the Cu²⁺ cation is a distorted trigonal bipyramid. The [H₂(Crypt-222)]²⁺ dication contains trifurcate N⁺-(…O)₃ bonds on axis 2.