During efforts to stabilize metal oxide bound chromophores for photoelectrochemical applications, a novel photochemical reaction has been discovered. In the reaction, the bisphosphonate functional groups -C(PO 3H2)2(OH) in the metal complex [Ru(bpy) 2(4,4′-(C(OH)(PO3H2)2bpy)] 2+ are converted into -COOH and H3PO4. The reaction occurs by sensitized formation of 1O2 by the lowest metal-to-ligand charge transfer excited state(s) of [Ru(bpy) 2(4,4′-(C(PO3H2)2(OH)) 2(bpy))]2+* followed by 1O2 oxidation of the bisphosphonate substituent. A related reaction occurs for the bisphosphonate-based drug, risedronic acid, in the presence of O2, light, and a singlet oxygen sensitizer ([Ru(bpy)3]2+ or Rose Bengal).
ASJC Scopus subject areas
- Colloid and Surface Chemistry