d-Orbital Reconstructions Forced by Double Bow-Shaped Deformations and Second Coordination Sphere Effects of Cu(II) Heme Analogs in HER.
Chemistry
; 28(8): e202103892, 2022 Feb 07.
Article
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| ID: mdl-34981568
ABSTRACT
Both geometric architecture and electronic configurations of heme proteins contribute to its activity. In this work we designed and synthesized a series of four copper(II) porphyrin complexes (4-, 3-, 2- and 1-Cu) where the molecular conformations are modulated by a pair of stepwise shortened straps on the same porphyrin side (cis-ortho) to give double bow-shaped skeletons. Single crystal structures demonstrate that the straps gradually increase the saddle deformation and the deviation of the metal centers, which is in accordance with two, unusual d-orbital reconstructions of two different ground states, as revealed by 4â
K EPR and DFT calculations. In the study of the electrocatalytic hydrogen evolution reaction (HER), 1-Cu, with the shortest straps, showed the most apparent improvement of activity. Second coordination sphere (SCS) effects created by the double bow-shaped architecture and the strong saddle porphyrin core in 1-Cu are found to play key roles in proton trapping during the catalytic process. The work contributes a novel strategy to improve the catalytic performance of heme analogs through ligand geometric modulation.
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Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Porfirinas
/
Hemoproteínas
Idioma:
En
Revista:
Chemistry
Asunto de la revista:
QUIMICA
Año:
2022
Tipo del documento:
Article