In:
Nature Communications, Springer Science and Business Media LLC, Vol. 10, No. 1 ( 2019-05-24)
Abstract:
The spin state transition from low spin to high spin upon substrate addition is one of the key steps in cytochrome P450 catalysis. External perturbations such as pH and hydrogen bonding can also trigger the spin state transition of hemes through deprotonated histidine (e.g. Cytochrome c ). In this work, we report the isolated 2-methylimidazole Cobalt(II) [Co(TPP)(2-MeHIm)] and [Co(TTP)(2-MeHIm)] , and the corresponding 2-methylimidazolate derivatives where the N−H proton of axial 2-MeHIm is removed. Interestingly, various spectroscopies including EPR and XAFS determine a high-spin state ( S = 3/2) for the imidazolate derivatives, in contrast to the low-spin state ( S = 1/2) of all known imidazole analogs. DFT assisted stereoelectronic investigations are applied to understand the metal-ligand interactions, which suggest that the dramatically displaced metal center allowing a promotion e g (d π ) → b 1g ( $$d_{x^2 - y^2}$$ d x 2 - y 2 ) is crucial for the occurrence of the spin state transition.
Type of Medium:
Online Resource
ISSN:
2041-1723
DOI:
10.1038/s41467-019-10357-z
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2019
detail.hit.zdb_id:
2553671-0
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