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Substitution effects on olefin epoxidation catalyzed by Oxoiron(IV) porphyrin π‐cation radical complexes: A dft study
Author(s) -
Ma Zhifeng,
Ukaji Kasumi,
Nakatani Naoki,
Fujii Hiroshi,
Hada Masahiko
Publication year - 2019
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.25831
Subject(s) - chemistry , porphyrin , fluorine , reactivity (psychology) , intersystem crossing , photochemistry , ethylene , olefin fiber , catalysis , ground state , density functional theory , polar effect , spin states , computational chemistry , medicinal chemistry , excited state , atomic physics , organic chemistry , inorganic chemistry , singlet state , physics , medicine , alternative medicine , pathology
The effects of peripheral fluorine atoms on epoxidation reactions of ethylene by oxoiron(IV) porphyrin cation radical complex in the quartet and sextet spin multiplicities are systematically investigated using the DFT method. The overall reaction routes are determined using a model system of ethylene and Fe(IV)OCl‐porphyrin with substituted fluorine atoms. By obtaining the energy diagrams and electron‐ and spin‐density difference contour maps of the transition states and intermediate compounds, we confirm that the electron‐withdrawing by peripheral fluorine atoms enhances the reactivity as the number of fluorine atoms increases, as is observed experimentally. The intersystem crossing between the quartet and sextet spin multiplicities is discussed by means of the intrinsic reaction coordinate method. We conclude that the rate‐determining step is located at the first transition state (TS1) for the activation of CC and FeO bonds, and the ground electronic state changes from quartet to sextet around the TS1. © 2019 Wiley Periodicals, Inc.