Fluorescence of clay-intercalated methylviologen

The elucidation of the effect of structure and composition of Ru(bpy)/sub 3//sup 2 +/ and of the function of each component on the photochemical processes may be assisted by a variety of spectroscopic studies. With this in mind the authors investigated the fluorescence behavior of methylviologen (MV). To the best of their knowledge fluorescence from MV at ambient temperatures has not been reported previously. However, fluorescence of MV/sup 2 +/ could be observed when it was incorporated into the lamellae of colloidal hectorite and montmorillonite suspensions. No fluorescence could be detected in the case of nontronite. Time-resolved fluorescence measurements as well as the fluorescence intensity variation with the ratio MV/sup 2 +//clay suggest different types of binding sites for MV/sup 2 +/ adsorbed on the clay colloidal particles.