This paper describes the preparation and photophysical characterization of hybrid materials made of a gamma-ZrP covalently pillared with two complexes: Ru(bpy)(2)L and Os(bpy)(2)L (bpy = 2,2'-bipyridine and L = 5,5'-bis(dihydroxyphosphoryl)-2,2'-bipyridine). A high degree of phosphate (H2PO4) exchange by the complexes in the gamma-ZrP matrix was achieved (25% intercalation) by preintercalating the gamma-ZrP with octylamine. Materials with different Os/Ru ratios were prepared, allowing the study of the efficiency of energy transfer as a function of the Ru/Os ratio (Ru/Os ratios = 1/0, 1/0.35, 1/0.6, 1/0.8, 1/1, and 0/1). Powder X-ray diffraction shows that the interlayer space of the intercalated gamma-ZrP is approximately 18.6 Angstrom in all of the intercalated materials. Solid-state P-31 NMR confirms that the complexes are covalently bonded to the zirconium of the gamma-ZrP phase. All of the materials exhibit moderately strong metal-to-ligand charge transfer (MLCT) emission from the Ru and/or Os chromophores. In the mixed samples the Ru-based emission is strongly quenched, indicating that in the gamma-ZrP matrix rapid Ru to Os energy transfer occurs. On the basis of the lifetimes of the Ru MLCT luminescence, the energy transfer rate is estimated to be 2-3 x 10(8) s(-1) for chromophores that are adjacent in the gamma-ZrP matrix.