From Tetranuclear 4-Oxo to 4-Peroxocopper(II) Complexes

Abstract

O substitution in 1. The tetranuclear copper(ii) complexes 1 and 4 are strongly antiferromagnetically coupled. They possess S 0 ground states separated from a triplet state by 510 and 720 cm À1, respectively. Good fits result from a regular spin Hamiltonian as well as from the Bleaney ± Bowers equation, which shows that only the two lowest-lying states are notably thermally populated. Magnetostructural correlations established for dimeric complexes are not easily transferable to these kinds of tetrameric complexes. Investigations in methanolic solution provide evidence that a tetranuclear m 4 -oxocopper(ii) complex analogous to 4 can be converted into a tetranuclear m 4 -peroxocopper-(ii) complex analogous to 1.

Reactivity of Copper(I) Complexes Towards Dioxygen

“…[15,35,36] By reacting a mixture of 2,6-bis(pyrrolidinomethyl)-4-methylphenol (L 3 , Scheme 2), copper(II) perchlorate, and triethylamine with hydrogen peroxide (or 3,5-di-tert-butylcatechol), these authors obtained a tetranuclear copper complex with the peroxo ligand bound end-on in a µ 4 -(η 1 ) 4 mode. When the same reaction was performed in the absence of hydrogen peroxide (or 3,5-di-tert-butylcatechol), a tetranuclear copperϪoxo complex with a µ 4 -O 2Ϫ unit was formed.…”

A Bio‐inspired Cu4O4 Cubane: Effective Molecular Catalysts for Electrocatalytic Water Oxidation in Aqueous Solution

“…Taken together,w ep resumed the generated EPR-silent species as the Cu III with al ow-spin configuration. [24] Thesame peak position at 875 cm À1 of the in situ generated and chemically generated species in their Raman spectra (Supporting Information, Figure S18) manifested the ñ(O À O) of the m 4 -coordinated peroxide. Thepresence of asignal at g = 2.0 in the in situ EPR spectra at 5K might be attributed to the anisotropy of g factor (g ?…”

A copper(II) complex with rare μ1,1,1-azide ligand: Active catalyst for heterogeneous olefin epoxidation

“…High TONs (turn over numbers = moles of substrate converted per mole of Cu) obtained for the substrates suggest a very high catalytic efficiency for the copper-hydroperoxo species that could be formed in presence of tert-butyl hydroperoxide. The existence of Cu-hydroperoxo species is evident from UVvis spectra with the peak at 395 nm with a shoulder in the region of 420-440 nm [16]. Corresponding diols (8-15%) from all the substrate were also produced during the oxidation.…”