Dioxygen activation and pyrrole α-cleavage with calix(4)pyrrolato aluminates: enzyme model by structural constraint
The present work describes the reaction of triplet dioxygen with the porphyrinogenic calix[4]pyrrolato aluminates to alkylperoxido aluminates in high selectivity. Multiconfigurational quantum chemical computations disclose the mechanism for this spin-forbidden process. Despite a negligible spin-orbi...
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| Main Authors: | , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
2021
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| In: |
Angewandte Chemie. International edition
Year: 2021, Volume: 60, Issue: 28, Pages: 15632-15640 |
| ISSN: | 1521-3773 |
| DOI: | 10.1002/anie.202104916 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1002/anie.202104916 Verlag, lizenzpflichtig, Volltext: https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202104916 |
| Author Notes: | Lukas Maximilian Sigmund, Christopher Ehlert, Markus Enders, Jürgen Graf, Ganna Gryn'ova, and Lutz Greb |
| Summary: | The present work describes the reaction of triplet dioxygen with the porphyrinogenic calix[4]pyrrolato aluminates to alkylperoxido aluminates in high selectivity. Multiconfigurational quantum chemical computations disclose the mechanism for this spin-forbidden process. Despite a negligible spin-orbit coupling constant, the intersystem crossing (ISC) is facilitated by singlet and triplet state degeneracy and spin-vibronic coupling. The formed peroxides are stable toward external substrates but undergo an unprecedented oxidative pyrrole α-cleavage by ligand aromatization/dearomatization-initiated O−O σ-bond scission. A detailed comparison of the calix[4]pyrrolato aluminates with dioxygen-related enzymology provides insights into the ISC of metal- or cofactor-free enzymes. It substantiates the importance of structural constraint and element-ligand cooperativity for the functions of aerobic life. |
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| Item Description: | First published: 06 May 2021 Gesehen am 29.11.2022 |
| Physical Description: | Online Resource |
| ISSN: | 1521-3773 |
| DOI: | 10.1002/anie.202104916 |