Dataset Information

New copper(II) μ-alkoxo-μ-carboxylato double-bridged complexes as models for the active site of catechol oxidase: synthesis, spectral characterization and DFT calculations.

ABSTRACT: A series of four copper(II) μ-Alkoxo-μ-carboxylato double bridged complexes, [{Cu₂(L)}₂][(μ-O₂C-CO₂] 1, [{Cu₂(L)}₂(μ-O₂C-(CH₂)CO₂] 2, [{Cu₂(L)}₂(μ-O₂C-CH₂-CO₂] 3 and [{Cu₂(L)}₂(μ-O₂C-C₆H₄-CO₂] 4 (H₃L = 4-bromo-2-((E)-((3-(((E)-5-chloro-2-hydroxybenzylidene) amino)-2-hydroxypropyl) imino) methyl)-6-methoxyphenol and μ-dicarboxylate ions = oxalate, malonate, succinate and terephthalate) have been synthesized and characterized using several physicochemical techniques. The tridentate nature of H₃L is interpreted from IR spectra. The Epr spectra of these complexes are characteristic of the quintet state (S = 2) in central features and the triplet state (S = 1) of these tetranuclear complexes. The electrochemical potential of these complexes was investigated using CV (cyclic voltammetry) and DPV (differential pulse voltammetry). All complexes showed quasi reversible reduction peaks in the cathodic region. To explore the stability of these complexes, quantum chemical parameters like electronegativity, ionization potential, electron affinity, global hardness and softness, and electrophilicity were estimated and discussed. The synthesized complexes have been designed as structural and functional models of the catechol oxidase enzymes to investigate the catecholase activity. Additionally, superoxide dismutase activity data of all complexes have also been evaluated and compared with known SOD mimics.

SUBMITTER: Patel AK

PROVIDER: S-EPMC9113650 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

New copper(II) μ-alkoxo-μ-carboxylato double-bridged complexes as models for the active site of catechol oxidase: synthesis, spectral characterization and DFT calculations.

Patel Abhay K AK Patel Neetu N Patel R N RN Jadeja Rajendra N RN

Heliyon 20220509 5

A series of four copper(II) μ-Alkoxo-μ-carboxylato double bridged complexes, [{Cu2(L)}2][(μ-O2C-CO2] 1, [{Cu2(L)}2(μ-O2C-(CH2)CO2] 2, [{Cu2(L)}2(μ-O2C-CH2-CO2] 3 and [{Cu2(L)}2(μ-O2C-C6H4-CO2] 4 (H3L = 4-bromo-2-((E)-((3-(((E)-5-chloro-2-hyd ...[more]

PMID: 35592663

Similar Datasets

Project description:The hydroxylation of aromatic substrates catalyzed by coupled binuclear copper enzymes has been observed with side-on-peroxo-dicopper(II) (P) and bis-?-oxo-dicopper(III) (O) model complexes. The substrate-bound-O intermediate in [Cu(II)2(DBED)2(O)2](2+) (DBED = N,N'-di-tert-butyl-ethylenediamine) was shown to perform aromatic hydroxylation. For the [Cu(II)2(NO2-XYL)(O2)](2+) complex, only a P species was spectroscopically observed. However, it was not clear whether this O-O bond cleaves to proceed through an O-type structure along the reaction coordinate for hydroxylation of the aromatic xylyl linker. Accurate evaluation of these reaction coordinates requires reasonable quantitative descriptions of the electronic structures of the P and O species. We have performed Cu L-edge XAS on two well-characterized P and O species to experimentally quantify the Cu 3d character in their ground state wave functions. The lower per-hole Cu character (40 ± 6%) corresponding to higher covalency in the O species compared to the P species (52 ± 4%) reflects a stronger bonding interaction of the bis-?-oxo core with the Cu(III) centers. DFT calculations show that 10-20% Hartree-Fock (HF) mixing for P and ~38% for O species are required to reproduce the Cu-O bonding; for the P species this HF mixing is also required for an antiferromagnetically coupled description of the two Cu(II) centers. B3LYP (with 20% HF) was, therefore, used to calculate the hydroxylation reaction coordinate of P in [Cu(II)2(NO2-XYL)(O2)](2+). These experimentally calibrated calculations indicate that the electrophilic attack on the aromatic ring does not involve formation of a Cu(III)2(O(2-))2 species. Rather, there is direct electron donation from the aromatic ring into the peroxo ?* orbital of the Cu(II)2(O2(2-)) species, leading to concerted C-O bond formation with O-O bond cleavage. Thus, species P is capable of direct hydroxylation of aromatic substrates without the intermediacy of an O-type species.

Project description:Layered materials, such as MoS2, are being intensely studied due to their interesting properties and wide variety of potential applications. These materials are also interesting as supports for low-dimensional metals for catalysis, while recent work has shown increased interest in using 2D materials in the electronics industry as a Cu diffusion barrier in semiconductor device interconnects. The interaction between different metal structures and MoS2 monolayers is therefore of significant importance and first-principles simulations can probe aspects of this interaction not easily accessible to experiment. Previous theoretical studies have focused particularly on the adsorption of a range of metallic elements, including first-row transition metals, as well as Ag and Au. However, most studies have examined single-atom adsorption or adsorbed nanoparticles of noble metals. This means there is a knowledge gap in terms of thin film nucleation on 2D materials. To begin addressing this issue, we present in this paper a first-principles density functional theory (DFT) study of the adsorption of small Cu n (n = 1-4) structures on 2D MoS2 as a model system. We find on a perfect MoS2 monolayer that a single Cu atom prefers an adsorption site above the Mo atom. With increasing nanocluster size the nanocluster binds more strongly when Cu atoms adsorb atop the S atoms. Stability is driven by the number of Cu-Cu interactions and the distance between adsorption sites, with no obvious preference towards 2D or 3D structures. The introduction of a single S vacancy in the monolayer enhances the copper binding energy, although some Cu n nanoclusters are actually unstable. The effect of the vacancy is localised around the vacancy site. Finally, on both the pristine and the defective MoS2 monolayer, the density-of-states analysis shows that the adsorption of Cu introduces new electronic states as a result of partial Cu oxidation, but the metallic character of Cu nanoclusters is preserved.

Dataset Information

New copper(II) μ-alkoxo-μ-carboxylato double-bridged complexes as models for the active site of catechol oxidase: synthesis, spectral characterization and DFT calculations.

Publications

New copper(II) μ-alkoxo-μ-carboxylato double-bridged complexes as models for the active site of catechol oxidase: synthesis, spectral characterization and DFT calculations.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets