X-ray Diffraction Patterns of Montmorillonite Oriented Films Exchanged with Enantiomeric and Racemic Tris(2,2′-Bipyridyl)Ruthenium(II)

Gilles Villemure
Department of Chemistry, University of New Brunswick, Bag Service #45222, Fredericton New Brunswick E3B 6E2, Canada

Abstract: X-ray diffraction patterns of oriented films of montmorillonite containing enantiomeric tris(2,2′-bipyridyl) ruthenium(II) chloride (Ru(bpy)22+) show a peak corresponding to basal spacings of approximately 27 Å. This peak is absent from the X-ray patterns of montmorillonite films containing racemic cations. A basal spacing of 27 Å is consistent with the adsorption of 2 layers of the enantiomeric cations in each interlayer space. Under the same condition only one layer of the raeemic cation was intercalated (basal spacings of 17.9 Å). These results are in accord with previous reports that montmorillonite can adsorb more of the optical isomers than of the racemic mixture of Ru(bpy)32+. Addition of NaCl to the mixtures resulted in an increase in the level of adsorption of the racemic cations and in the appearance of a peak at 27 Å in the X-ray pattern.

Key Words: Double layer • Enantiomorphs • Intercalation • Monolayer • Montmorillonite • Surface area • Tris(2,2′-bipyridyl)ruthenium(II) • X-rays

Clays and Clay Minerals; December 1991 v. 39; no. 6; p. 580-585; DOI: 10.1346/CCMN.1991.0390603
© 1991, The Clay Minerals Society
Clay Minerals Society (www.clays.org)