Abstract We report the preparation of a MCM-41 mesoporous material that contains the dye [Ru (bipy) 3] Cl 2 (bipy= bipyridine) inside the mesopores and functionalised with suitable binding groups at the entrance of the pores. Solids S1–S3 were obtained by the reaction of the mesoporous material with N-methyl-N′-propyltrimethoxysilylimidazolium chloride, N- phenyl-N′-[3-(trimethoxysilyl) propyl] thiourea, or N-phenyl-N′-[3-(trimethoxysilyl) propyl ...