Synthesis and Crystal Structure of Hexaaquamagnesium 18-Crown-6 Dibromide Dihydrate

摘要

A new complex compound [Mg(H2O)6]Br2 centre dot 18-crown-6 centre dot 2H2O(I) is synthesized, and its structure is studied by X-ray diffraction analysis. The crystals are monoclinic: space group P2_1/c, a - 7.128 A,b= 18.584 A, c = 9.598 A, beta = 103.01~(deg), Z = 2; R = 0.039 for 2180 independent reflections (CAD-4 automated diffractometer, lambdaMoK_(alpha) radiation). The coordination polyhedron of the Mg~(2+) cation is a slightly distorted octahedron. The 18-crown-6 molecule has the conformation of a distorted crown with the approximate D_(3d) symmetry. The crystal contains a branched three-dimensional network of intermolecular (interionic) hydrogen bonds.