Cyclic voltammetric and fiber-optic infrared spectroelectrochemical studies of six-coordinate (por)Ru(NO)Cl compounds (por = porphyrinato dianion)

The redox behavior of representative (por)Ru(NO)Cl complexes (por = OEP, T(p-OMe)PP, T(p-CF3)PP) have been obtained. The compounds possess linear RuNO moieties as exemplified by the X-ray crystal structure of (T(p-OMe)PP)Ru(NO)Cl (Ru–N–O = 174(2)°, Ru–N(O) = 1.790(17) Å, Ru–Cl = 2.220(6) Å). The first electrooxidations of the (por)Ru(NO)Cl compounds in CH2Cl2 occur in the order OEP (+0.51 V) < T(p-OMe)PP (+0.57 V) < T(p-CF3)PP (+0.84 V) (versus Fc/Fc+). We have utilized infrared reflectance spectroelectrochemistry to determine that the first oxidations are porphyrin centered. In addition, the reductions are largely RuNO centered.

The IR spectroelectrochemical behavior of three (por)Ru(NO)Cl complexes reveal porphyrin centered first oxidations; the crystal structure of (T(p-OMe)PP)Ru(NO)Cl confirms the linear Ru–N–O linkage.Figure optionsDownload as PowerPoint slideHighlights
► We have determined the redox behavior of three (porphyrin)Ru(NO)Cl compounds.
► Infrared spectroelectrochemistry was used to characterize the redox products.
► The first oxidations of these compounds occur on the porphyrin macrocycles.