Abstract
The crystal structure of all-facial-[Co(hexacyclen)](NO3)3·H2 (the geometric isomer which elutes first on cation exchange chromatography) is reported. In the centrosymmetric cation the cobalt(III) atom exists in a slightly distorted octahedron, and the cation has approximate C 3 symmetry. The Co-N distances average 1.997(3) Å and the average chelate angle is 83.6(1)°. In the crystal lattice the complex cations are linked by water molecules of crystallization thereby forming infinite chains and the nitrate groups are associated to both the cation and the water molecule. The compound crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 13.980(4), b = 9.892(2), c = 16.002(6) Å, β = 111.34(4)° and Z = 4. The structure was refined by a full-matrix least-squares procedure to final R = 0.037 for 1183 reflections with I ≥ 2.5 σ(I).