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Biomimetic Hydroxylation Catalysis Through Self‐Assembly of a Bis(pyrazolyl)methane Copper–Peroxo Complex
Author(s) -
Wilfer Claudia,
Liebhäuser Patricia,
Erdmann Hannes,
Hoffmann Alexander,
HerresPawlis Sonja
Publication year - 2015
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201402957
Subject(s) - chemistry , natural bond orbital , hydroxylation , catalysis , ligand (biochemistry) , copper , methane , medicinal chemistry , density functional theory , stereochemistry , crystallography , photochemistry , computational chemistry , organic chemistry , biochemistry , receptor , enzyme
We synthesised and characterised four copper complexes (with copper in the oxidation states I and II) with the bis(pyrazolyl)methane ligands HC(3‐ t BuPz) 2 (Py) and HC(3‐ t BuPz) 2 (Qu). With the quinolinyl ligand (2‐quinolinyl)bis(3‐ tert ‐butylpyrazolyl)methane [HC(3‐ t BuPz) 2 (Qu)] we obtained the tetrahedral monofacial complex [CuCl{HC(3‐ t BuPz) 2 (Qu)}] ( C1 ) and with the pyridinyl ligand (2‐pyridinyl)bis(3‐ tert ‐butylpyrazolyl)methane [HC(3‐ t BuPz) 2 (Py)] we obtained the three complexes [CuCl{HC(3‐ t BuPz) 2 (Py)}] ( C2 ), [CuBr 2 {HC(3‐ t BuPz) 2 (Py)}] ( C3 ) and [CuCl 2 {HC(3‐ t BuPz) 2 (Py)}] ( C4 ), which are also monofacially coordinated. The molecular structures were analysed and compared with density functional theory calculations, which included natural bond orbital (NBO) analysis. C1 can, when generated in situ, serve as part of a precursor, used for the activation of oxygen as tyrosinase model. We observe the self‐assembly of a peroxo–dicopper complex P with the HC(3‐ t BuPz) 2 (Qu) ligand, which is able to perform catalytic hydroxylation catalysis with phenols. DFT calculations were also carried out to understand the electronic transitions responsible for the UV/Vis bands in the corresponding spectra of the peroxo species.