Oxidation and Catalytic Properties of a Binuclear Copper(i) Complex With a Meta-Xylyl Spacer Ligand

Calero, Rolando; Vega, Andrés; García, Ana María; Spodin, Evgenia; Manzur, Jorge

doi:10.4067/s0717-97072003000200015

Cited by 21 publications

(7 citation statements)

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“…Kinetic measurements were made spectrophotometrically on UV-Vis spectrophotometer, following the appearance of o-quinone over time at 25°C (390 nm absorbance maximum, ε = 1600 L mol -1 cm -1 in methanol [28]. The complexes were prepared in situ by successively mixing 0.3 mL of a solution (2.…”

Section: Catecholase Activity Measurementsmentioning

confidence: 99%

Synthesis, X-ray crystallography, computational studies and catecholase activity of new zwitterionic Schiff base derivatives

Boulemche

Anak

Djedouani

et al. 2019

Journal of Molecular Structure

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Three new Schiff bases compounds (L1-L2-L3) were synthesized by a condensation reaction in 1:1 molar ratios of dehydroacetic acid (3-acetyl-6-methyl-2H-pyran-2,4(3H)-dione) and 4-fluoro/4chloro/4-bromo aniline in ethanol, the products were obtained in excellent yields. Their structures were characterized by spectroscopic techniques (FT-IR and 1H-NMR) and single-crystal X-ray diffraction. The three compounds display zwitterionic forms, with cationic iminium and anionic enolate groups.The aromatic ring and dehydroacetic acid ring are in a trans position with respect to the C=N bond. Calculations in the framework of the density-functional theory (DFT) were carried out to determine the optimized structures and electronic properties as the HOMO-LUMO energy gap.Hirshfeld surface analysis was used to support the packed crystal lattice 3D network intermolecular forces. The NH form is found to be more stable than OH form. On the other hand, the in situ generated copper (II) complexes were examined for their catalytic activities and were found to catalyze the oxidation reaction of catechol to o-quinone under atmospheric dioxygen. The present study reveals that the rate of oxidation depends on the nature of the substituents in the phenyl ring, the counter anion and the concentration of ligand. The combination L1(Cu(CH3COO)2) gives the highest rate.

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Section: Catecholase Activity Measurementsmentioning

confidence: 99%

Synthesis, X-ray crystallography, computational studies and catecholase activity of new zwitterionic Schiff base derivatives

Boulemche

Anak

Djedouani

et al. 2019

Journal of Molecular Structure

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“…Copper complexes − and especially those with multinuclear cores − are well known to catalyze the oxidation reactions of different organic compounds with peroxides. Multicopper compounds are often more active than monocopper derivatives .…”

Section: Resultsmentioning

confidence: 99%

Acetone Factor in the Design of Cu₄-, Cu₆-, and Cu₉-Based Cage Coppersilsesquioxanes: Synthesis, Structural Features, and Catalytic Functionalization of Alkanes

et al. 2022

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The present study describes a new feature in the self-assembly of cagelike copperphenylsilsesquioxanes: the strong influence of acetone solvates on cage structure formation. By this simple approach, a series of novel tetra-, hexa-, or nonacoppersilsesquioxanes were isolated and characterized. In addition, several new complexes of Cu4 or Cu6 nuclearity bearing additional nitrogen-based ligands (ethylenediamine, 2,2′-bipyridine, phenanthroline, bathophenanthroline, or neocuproine) were produced. Single-crystal X-ray diffraction studies established molecular architectures of all of the synthesized products. Several coppersilsesquioxanes represent a novel feature of cagelike metallasilsesquioxane (CLMS) in terms of molecular topology. A Cu4–silsesquioxane complex with ethylenediamine (En) ligands was isolated via the unprecedented self-assembly of a partly condensed framework of silsesquioxane ligands, followed by the formation of a sandwich-like cage. Two prismatic Cu6 complexes represent the different conformersregular and elliptical hexagonal prisms, “cylinders”, determined by the different orientations of the coordinated acetone ligands (“shape-switch effect”). A heterometallic Cu4Na4-sandwich-like derivative represents the first example of a metallasilsesquioxane complex with diacetone alcohol ligands formed in situ due to acetone condensation reaction. As a selected example, the compound [(Ph6Si6O11)2Cu4En2]·(acetone)2 was explored in homogeneous oxidation catalysis. It catalyzes the oxidation of alkanes to alkyl hydroperoxides with hydrogen peroxide and the oxidation of alcohols to ketones with tert-butyl hydroperoxide. Radical species take part in the oxidation of alkanes. Besides, [(Ph6Si6O11)2Cu4En2]·(acetone)2 catalyzes the mild oxidative functionalization of gaseous alkanes (ethane, propane, n-butane, and i-butane). Two different model reactions were investigated: (1) the oxidation of gaseous alkanes with hydrogen peroxide to give a mixture of oxygenates (alcohols, ketones, or aldehydes) and (2) the carboxylation of C n gaseous alkanes with carbon monoxide, water, and potassium peroxodisulfate to give C n+1 carboxylic acids (main products), along with the corresponding C n oxygenates. For these reactions, the effects of acid promoter, reaction time, and substrate scope were explored. As expected for free-radical-type reactions, the alkane reactivity follows the trend C2H6 < C3H8 < n-C4H10 < i-C4H10. The highest total product yields were observed in the carboxylation of i-butane (up to 61% based on i-C4H10). The product yields and catalyst turnover numbers (TONs) are remarkable, given an inertness of gaseous alkanes and very mild reaction conditions applied (low pressures, 50–60 °C temperatures).

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“…A solution of the metal complex (prepared in situ from an appropriate copper salt and the ligand; 0.3 ml of a 10 -3 M methanol solution) [28] and a solution of 3,5-ditert-butylcatechol (2 ml of a 10 -1 M methanol solution) were mixed in the spectrophotometric cell.…”

Section: Methodsmentioning

confidence: 99%

“…The metal complex (prepared in situ from a copper salt and the ligand) [28] and a solution of 3,5-di-tert-butylcatechol were mixed together in the spectrophotometric cell at 25 °C. Formation of 3,5-di-tertbutylquinone was monitored by following the increase in absorbance at 400 nm as a function of time.…”

Section: Effect Of the Nature Of The Junction On The Catecholase Actimentioning

confidence: 99%

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Effect of two isomeric tetrapyrazolyl ligands on the catalytic oxidation of 3,5-di-tert-butylcatechol

Bouabdallah

Touzani

Zidane

et al. 2007

JICS

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Copper(II) salts were combined with a tetrapyrazolyl ligand ({N,N,N',N'-tetrakis-[(3,5-and assessed as oxidation catalysts. The corresponding dioxygen complexes were generated in situ by mixing the copper salt and the pyrazolyl donor ligand in air. The oxidation of 3,5-di-tert-butylcatechol (DTBC), which affords 3,5-di-tert-butylquinone (DTBQ), was studied. The reaction rate was found to depend essentially on the nature of the junction linking two pyrazolyl neighbours.

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Oxidation and Catalytic Properties of a Binuclear Copper(i) Complex With a Meta-Xylyl Spacer Ligand

Cited by 21 publications

References 0 publications

Synthesis, X-ray crystallography, computational studies and catecholase activity of new zwitterionic Schiff base derivatives

Synthesis, X-ray crystallography, computational studies and catecholase activity of new zwitterionic Schiff base derivatives

Acetone Factor in the Design of Cu₄-, Cu₆-, and Cu₉-Based Cage Coppersilsesquioxanes: Synthesis, Structural Features, and Catalytic Functionalization of Alkanes

Effect of two isomeric tetrapyrazolyl ligands on the catalytic oxidation of 3,5-di-tert-butylcatechol

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Oxidation and Catalytic Properties of a Binuclear Copper(i) Complex With a Meta-Xylyl Spacer Ligand

Cited by 21 publications

References 0 publications

Synthesis, X-ray crystallography, computational studies and catecholase activity of new zwitterionic Schiff base derivatives

Synthesis, X-ray crystallography, computational studies and catecholase activity of new zwitterionic Schiff base derivatives

Acetone Factor in the Design of Cu4-, Cu6-, and Cu9-Based Cage Coppersilsesquioxanes: Synthesis, Structural Features, and Catalytic Functionalization of Alkanes

Effect of two isomeric tetrapyrazolyl ligands on the catalytic oxidation of 3,5-di-tert-butylcatechol

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Acetone Factor in the Design of Cu₄-, Cu₆-, and Cu₉-Based Cage Coppersilsesquioxanes: Synthesis, Structural Features, and Catalytic Functionalization of Alkanes