A DFT and multi-configurational perturbation theory study on O₂ binding to a model heme compound via the spin-change barrier

• Kitagawa, Y.

• Chen, Y.

• Nakatani, Naoki

• Nakayama, Akira

• Hasegawa, Jun-ya

書誌事項

タイトル別名

• A DFT and multi-configurational perturbation theory study on O-2 binding to a model heme compound via the spin-change barrier

抄録

Dioxygen binding to a model heme compound via intersystem crossing (ISC) was investigated with a multi-state multi-configurational self-consistent field method with second-order perturbation theory (MS-CASPT2) and density functional theory (DFT) calculations. In elongated Fe-O distances, the energy levels of the S-0 and T-1 states are separated, which decreases the probability of intersystem crossing in these structures. At the DFT(B97D) level of calculation, the Fe-O distances of the S-0 and T-1 states were 1.91 and 2.92 angstrom, respectively. The minimum energy intersystem crossing point (MEISCP) was located as a transition state at a Fe-O distance of 2.17 angstrom with an energy barrier of 1.0 kcal mol(-1) from the T-1 minimum. The result was verified with MS-CASPT2 calculations including the spin-orbit interaction which also showed the intersystem crossing point at a Fe-O distance of 2.05 angstrom. An energy decomposition analysis on the reaction coordinate showed the important contribution of the ring-shrinking mode of the porphyrin ring, indicating that the reaction coordinates which control the relative energy level of the spin-states play a key role in intersystem crossing.

収録刊行物

• Physical chemistry chemical physics

  Physical chemistry chemical physics 18 (27), 18137-18144, 2016-07-21

  Royal Society of Chemistry

キーワード

• Physical and Theoretical Chemistry
• General Physics and Astronomy

詳細情報

• CRID: 1050845763950753024
• NII論文ID: 120006324911
• DOI: 10.1039/c6cp02329k
• ISSN: 14639084
• ISSN: 14639076
• HANDLE: 2115/66640
• Web Site: http://pubs.rsc.org/en/content/articlepdf/2016/CP/C6CP02329K
• 本文言語コード: en
• 資料種別: journal article
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