77944-58-2Relevant academic research and scientific papers
Dioxygen and nitric oxide complexes of rhodium porphyrins
Wayland, Bradford B.,Newman, Alan R.
, p. 3093 - 3097 (1981)
(RhOEP)2 (OEP = octaethylporphyrin) reacts with dioxygen to form RhOEP(O2) (S = 1/2). which subsequently forms the μ-peroxo complex (RhOEP)2O2. EPR studies of RhOEP(O2) and RhTPP(O2) (TPP = tetraphenylporphyrin) and their 1:1 donor complexes are reported and compared with those of the cobalt analogues. (RhOEP)2, RhOEP(H), and RhOEP(Cl) all react with nitric oxide to ultimately produce the same product, RhOEP(NO). The reactions of RhOEP(Cl) and RhTPP(Cl) with nitric oxide proceed through a metastable paramagnetic intermediate Rh(por)(Cl)(NO) (por = porphyrin), which from EPR and electronic spectral studies is formulated as containing a porphyrin π-cation radical unit with an 2A1u ground state. RhOEP(NO)(Cl) associates to form a radical dimer (S = 1) with D = 5.17 × 10-3 cm-1 and E = 2.4 × 10-4 cm-1, but only monomeric RhTPP(NO)(Cl) is observed. Electrochemical studies of rhodium(III) porphyrins also support the porphyrin cation radical formulation for Rh(por)(NO)(Cl) complexes.
