Crystal structures of complexes between alkali-metal salts and cyclic polyethers. Part VI. Complex formed between dicyclohexyl-18-crown-6, isomer B, (perhydrodibenzo[b,k][1,4,7,10,13,16]hexaoxacyclo-octadecin) and sodium bromide

Abstract

A three-dimensional X-ray crystal structure analysjs has been carried out on the title complex, [Na(C₂₀H₃₆O₆)(H₂O)₂]Br. Crystals are triclinic. Space group P, with a= 10·32(1), b= 11·34(1), c= 6·67(1)Å, α= 116° 42′(6′), β= 109° 48′(5′), γ= 100° 10′(6′). The sodium ion lies on a centre of symmetry, and is surrounded by an approximately planar ring of six oxygen atoms of one ligand. (Na^–O 2·67–2·97 Å). The hexagonal bipyramidal arrangement about the sodium is completed by two water molecules, at 2·34 Å. The water molecules form hydrogen bonds to the bromide ion, resulting in an infinite chain structure.

1366 Intensities measured on a diffractometer were refined by full-matrix least-squares to R 0·046. All hydrogen atoms were located, except that involved in the hydrogen bond.