The activation of chemical bonds in molecules on photochemically produced Rh-I sites is reviewed in this article. The focus is primarily on the Rh-I(CO) species generated during the ultraviolet photolysis of the well-known Rh-I(CO)(2) species supported on an aluminum oxide surface (designated Rh-I(CO)(2)/Al2O3). The Rh-I(CO)(2) surface species is the heterogeneous analogue of the homogeneous phase CpRh(CO)(2) and CpRh(CO)(2) (Cp* = eta(5)-C-5(CH3)(5); CP = eta(5)-C5H5) known for its ability to activate the C-H bond in alkanes during ultraviolet irradiation. Here we review some of the key studies that have led to the molecular understanding of the activation of the Rh-I(CO)(2)/Al2O3 species by photochemical methods. Relevant examples of the homogeneous-phase bond activation studies utilizing a rhodium center will be discussed as well as theoretical studies that have provided valuable information regarding the active nature of the photoproduced Rh site. This will be followed by a review of recent photochemical studies of surface-bound Rh-I(CO)(2). The coordinatively unsaturated Rh-I(CO) species produced photochemically can activate the C-H bond in C6H12 and CH4, the H-H bond in H-2, the O=O bond in O-2, and the C=O bond in CO2.