Stereoselective Enhancement of VCD Signals for Intercalation Compounds of Sodium Montmorillonite and Chiral Metal Complexes

Abstract

Vibrational circular dichroism (VCD) spectra were recorded for the intercalation compounds of sodium montmorillonite co-adsorbing two kinds of metal complexes, -(or ª-)[Ru-(phen)3]2+ and -(or)[Ni(phen)3]2+. The complexes were chosen so as to form a pseudo racemate. Notably some of the VCD signals were enhanced in comparison to the samples adsorbing each complex separately. The results were rationalized in terms of the delocalization of vibrational motions over a tightly bound molecular pair in a coherent way. The model of racemic adsorption of [M(II)(phen)3]2+ (M(II) =a divalent metal ion) in the interlayer space of a clay mineral was proposed.