Extended hartree-fock theory of chemical reactions. VIII. hydroxylation reactions by P450

Hiroshi Isobe, Satomichi Nishihara, Mitsuo Shoji, Shusuke Yamanaka, Jiro Shimada, Masayuki Hagiwara, Kizashi Yamaguchi

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

We have investigated the reaction pathways for the primary hydroxylation reaction of trimethylmethane by a high-valent Fe(IV)=O porphyrin π-cation radical species known as compound I at the B3LYP/CEP-31G level. The isoelectronic analogy of the Fe(IV)=O core of compound I to a molecular oxygen (O2) has been successfully used to clarify the important roles of the singlet excited state of the Fe(IV)=O core in the alkane hydroxylation, which has hitherto been neglected. The reaction is initiated by the rate-determining hydrogen-atom abstraction from the substrate to give a discrete radical intermediate complex, in accordance with the conventional radical rebound mechanism. Similar to the chemistry of O2, however, one of the singlet excited states, i.e., the diradical component of the 1Δ state of the Fe(TV)=O core intercepts the triplet ground state (the 3Σ state) in the region of the transition state for the hydrogen abstraction. Our findings strongly indicate that the exchange polarization or intersystem crossing for the nonradiative transition to the locally singlet state is highly important to enhance the reactivity of compound I.

Original languageEnglish
Pages (from-to)2991-3009
Number of pages19
JournalInternational Journal of Quantum Chemistry
Volume108
Issue number15
DOIs
Publication statusPublished - 2008
Externally publishedYes

Fingerprint

Hydroxylation
Excited states
Chemical reactions
Hydrogen
chemical reactions
Alkanes
Molecular oxygen
Porphyrins
Ground state
Cations
Polarization
porphyrins
Atoms
alkanes
excitation
hydrogen atoms
Substrates
reactivity
chemistry
cations

Keywords

  • Compound I
  • Density-functional theory
  • Hydroxylation reaction
  • Nonradiative transition
  • P450

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Atomic and Molecular Physics, and Optics
  • Physical and Theoretical Chemistry

Cite this

Isobe, H., Nishihara, S., Shoji, M., Yamanaka, S., Shimada, J., Hagiwara, M., & Yamaguchi, K. (2008). Extended hartree-fock theory of chemical reactions. VIII. hydroxylation reactions by P450. International Journal of Quantum Chemistry, 108(15), 2991-3009. https://doi.org/10.1002/qua.21874

Extended hartree-fock theory of chemical reactions. VIII. hydroxylation reactions by P450. / Isobe, Hiroshi; Nishihara, Satomichi; Shoji, Mitsuo; Yamanaka, Shusuke; Shimada, Jiro; Hagiwara, Masayuki; Yamaguchi, Kizashi.

In: International Journal of Quantum Chemistry, Vol. 108, No. 15, 2008, p. 2991-3009.

Research output: Contribution to journalArticle

Isobe, H, Nishihara, S, Shoji, M, Yamanaka, S, Shimada, J, Hagiwara, M & Yamaguchi, K 2008, 'Extended hartree-fock theory of chemical reactions. VIII. hydroxylation reactions by P450', International Journal of Quantum Chemistry, vol. 108, no. 15, pp. 2991-3009. https://doi.org/10.1002/qua.21874
Isobe, Hiroshi ; Nishihara, Satomichi ; Shoji, Mitsuo ; Yamanaka, Shusuke ; Shimada, Jiro ; Hagiwara, Masayuki ; Yamaguchi, Kizashi. / Extended hartree-fock theory of chemical reactions. VIII. hydroxylation reactions by P450. In: International Journal of Quantum Chemistry. 2008 ; Vol. 108, No. 15. pp. 2991-3009.
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