Fabrication of hybrid Langmuir–Blodgett films consisting of a smectite clay and a nonamphiphilic chiral ruthenium(II) complex

We fabricated hybrid Langmuir–Blodgett (LB) films of a smectite clay and chiral tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) perchlorate which has no long alkyl chain. Characteristics of the films were compared with those of the films consisting of a racemic mixture of the same complexes by means of pressure–area (π–A) isotherm measurements, linear and nonlinear optical spectroscopies and atomic force microscopy (AFM). Similar to the case with the films of the racemic metal complex, the density of the chiral metal complexes adsorbed onto the surface of the clay sheet was found to be controlled by changing the film fabrication conditions. The optical second-harmonic generation circular-dichroism (SHG-CD) response from a chiral film indicated the existence of a chiral molecular array on the surface of the clay sheets.