Coadsorption Studies of Tris(1,10-phenanthroline)ruthenium(II) and N-Methylated Alkaloid Cation by Laponite with an Application for a Chiral Column Packing Material

Abstract

Coadsorption studies of chiral tris(1,10-phenanthroline)ruthenium(II) ([Ru(phen)3]2+) and N-methylated cinchona alkaloid cation (MQN+) were conducted on a smectite clay by ion exchange reactions. Photoinduced energy transfer between these cations was confirmed by the photoluminescence spectra, indicating that the cations were co-intercalated in the interlayer space of a smectite. When a ternary ion-exchanged adduct of [Ru(phen)3]2+/MQN+/smectite was employed as a packing material for liquid chromatography, the column proved to resolve a racemic mixture of 1,1‘-binaphthol more effectively than the column packed with a binary adduct of [Ru(phen)3]2+/smectite. The results reflected the enhancement of the chiral discrimination ability through the cooperative interactions among two kinds of preadsorbed chiral cations.