Synthesis, Characterization, and Infrared Reflectance Spectroelectrochemistry of Organoruthenium Nitrosyl Porphyrins

Metal–carbon bonds are known to form during the metal-catalyzed transformations of various organic compounds such as phenylhydrazines by the heme-containing proteins cytochrome P450, hemoglobin, and myoglobin. The preparation and characterization of synthetic organometallic porphyrins of the group 8 metals are thus of interest, and their properties help enlighten the general discussion of metalloporphyrin–carbon bond chemistry. We have prepared a representative set of (por)­Ru­(NO)­R compounds (por = T­(p-OMe)­PP, T­(p-CF3)­PP; R = Me, Et) containing Ru–alkyl bonds trans to NO. We have determined the X-ray crystal structure of (T­(p-OMe)­PP)­Ru­(NO)­Et, which represents the first crystal structure reported for any organometallic nitrosyl porphyrin with an alkyl ligand trans to NO; the structure reveals a significantly bent RuNO moiety at 153° in this {RuNO}6 compound. We have characterized the redox behavior of the (T­(p-OMe)­PP)­Ru­(NO)-containing compounds by cyclic voltammetry and infrared spectroelectrochemistry, and we have determined that the first oxidations are porphyrin-centered.