American Chemical Society
The 1H NMR spectra of Fe(OEP)(HNO), which was formed from Fe(OEP)(NO)− in the presence of 3,5-dichlorophenol, were studied as a function of temperature. The chemical shift of the HNO proton showed a unique behavior which could be explained based on the equilibrium between the protonated complex, Fe(OEP)(HNO), and the hydrogen-bonded complex, Fe(OEP)(NO)−···HOPh. This equilibrium was consistent with UV/visible spectroscopy and the voltammetric data. UV/visible stopped-flow experiments showed that the hydrogen-bonded complex, which was formed when weak acids such as phenol were added, and the Fe(OEP)(HNO) complex were quite similar. In addition to the HNO proton resonance, the meso-resonances were consistent with the proposed equilibrium. Density functional theory calculations of various Fe(OEP)(NO)−/Fe(OEP)(HNO) species were calculated, and the results were consistent with experimental data.
Rahman, Md. Hafizur; Liu, Yilin; and Ryan, Michael D., "Proton Transfer versus Hydrogen Bonding in a Reduced Iron Porphyrin Nitrosyl Complex" (2019). Chemistry Faculty Research and Publications. 989.
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