Tris (1, 10-phenanthroline) Rhodium (III) is incorporated in the interlayer space of clay mineral, which has layered structure, by ion-exchange intercalation. This intercalation compound shows the strong absorption band around the visible region when irradiated with UV-light in the presence of triethanolamine. The spectral change is caused by the photoreduction of organometallic complex ions fixed in the interlayer spaces and the reduced species remain stable after the irradiation. A new type of optical memory can be made with this compound in the form of thin film. X-ray photoelectron spectroscopy proved to be a suitable method to observe a topochemical behavior of the intercalation process as well as to detect the reduced state of interlayer species directly.
