Synthesis and crystal structure of octaaqua(di-μ-bromo)dimanganese(II) dibromide 18-crown-6

Abstract

A new crystalline complex octaaqua(di-μ-bromo)dimanganese(II) dibromide 18-crown-6, [Mn2Br2(H2O)8]Br2 · 18C6, is synthesized and studied by X-ray diffraction analysis. The crystals of compound I are triclinic, space group $$P\bar 1$$ , a = 9.093 A, b = 9.683, A, c = 10.032 A, α = 111.35°, β = 116.23°, γ = 92.64°, Z = 1. The structure is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.028 for 3276 independent reflections (CAD4 automated diffractometer, λMoK α radiation). The [Mn2Br2(H2O)8]2+ complex cation lying at the inversion center is binuclear with two bridging Br atoms and eight water molecules. The coordination polyhedron of one Mn2+ cation is a distorted cis-octahedron with two Br atoms and four O atoms of the water molecules at its corners. The centrosymmetric 18C6 molecule has an usual conformation. A crystal of compound I contains a developed three-dimensional network of intermolecular (interionic) hydrogen bonds.