(Dibenzo-18-Crown-6)ammonium bromide tetrahydrofuran solvate: Synthesis and crystal structure

Abstract

A new compound, (dibenzo-18-crown-6)ammonium bromide tetrahydrofuran solvate [NH₄(Db18C6)]⁺ · Br⁻ · THF (I), is synthesized and studied by X-ray diffraction analysis. The crystals of compound I are triclinic: a = 8.848 Å, b = 9.696 Å, c = 16.023 Å, α = 73.75°, β = 86.93°, γ = 78.06°, Z = 2, space group P $\bar 1$. The structure of compound I is solved by a direct method and refined by full-matrix least squares in the anisotropic approximation to R = 0.095 by 5624 independent reflections (CAD-4 automated diffractometer, γMoK _α). The Db18C6 molecule in structure I has a butterfly conformation with approximate symmetry C _2v . The NH ⁺₄ cation where three disordered H atoms form hydrogen bonds with all six O atoms of the Db18C6 molecule is situated in the center of the cavity of the eighteen-membered macrocycle of the Db18C6 molecule. One ordered H atom of the NH ⁺₄ cation forms a strong hydrogen bond with the Br⁻ anion.