Switching of energy transfer reaction by the control of orientation factor between porphyrin derivatives on the clay surface

•Photochemical energy transfer was examined on the flat clay surface.•The molecular adsorption orientation angle of dyes can be modulated.•The energy transfer efficiency between dyes can be controlled by the relative orientation change between dyes.•The change of orientation and spectral overlap factor affects the energy transfer efficiency. Photochemical energy transfer was examined on the flat clay surface. By the change of surrounding atmosphere, the molecular adsorption orientation angle of dyes can be modulated. It is turned out that the energy transfer efficiency between dyes can be controlled by the relative orientation change between dyes. The change of orientation factor and spectral overlap factor was the main factor to affect the energy transfer efficiency. This technique would be useful to construct the photo-functional materials such as chromic and light harvesting system.