Crystal structures of complexes between alkali-metal salts and cyclic polyethers. Part III. Aquo-(2,3-benzo-1,4,7,10,13-pentaoxacyclopentadec-2-ene)sodium iodide

Abstract

The crystal structure of the title complex determined from three-dimensional diffractometer data. Z= 4 in an orthorhambic unit cell having a= 12·271, b= 9·550, c= 15·719 Å, and space group P2₁2₁2₁. Full-matrix least-squares refinement based on 887 observations has led to R 0·048 for the correct absolute configuration of the molecule.

The sodium ion is surrounded by a pentagonal pyramid of oxygen atoms. The base is formed by those of the cyclic ether with Na–O 2·35(1)–2·43(1)Å and the sodium ion is 0·75 Å from this plane towards the apical water molecule, Na–O 2·29(1)Å. The iodide ion does not interact with the sodium ion but may form hydrogen bonds to water molecules [O⋯I 3·47(1) and 3·51(1)Å], linking the complexes in chains along the b-axis of the crystal.