High-Valent d Ni versus d Cu Oxidants in PCET.

Oxygenases have been postulated to utilize d Fe and d Cu oxidants in proton-coupled electron transfer (PCET) hydrocarbon oxidation. In order to explore the influence the metal ion and d-electron count can hold over the PCET reactivity, two metastable high-valent metal-oxygen adducts, [Ni(OAc)(L)] () and [Cu(OAc)(L)] (), L = ,-(2,6-diisopropylphenyl)-2,6-pyridinedicarboxamidate, were prepared from their low-valent precursors [Ni(OAc)(L)] () and [Cu(OAc)(L)] (). The complexes /-/ were characterized using nuclear magnetic resonance, Fourier transform infrared, electron paramagnetic resonance, X-ray diffraction, and absorption spectroscopies and mass spectrometry.

A Mn Mn -Peroxide Complex Capable of Aldehyde Deformylation.

Ribonucleotide reductases (RNRs) are essential enzymes required for DNA synthesis. In class Ib Mn RNRs superoxide (O ) was postulated to react with the Mn core to yield a Mn Mn -peroxide moiety. The reactivity of complex 1 ([Mn (O CCH ) (BPMP)](ClO ), where HBPMP=2,6-bis{[(bis(2-pyridylmethyl)amino]methyl}-4-methylphenol) towards O was investigated at -90 °C, generating a metastable species, 2.

Catechol oxidase activity of comparable dimanganese and dicopper complexes.

Synthetic Cu complexes have been widely investigated as model systems for catechol oxidase enzymes. The catechol oxidase reactivity of Mn complexes has been less explored, and the effect of metal substitution in catecholase mimics has not been explored. A series of Mn and Cu complexes supported by the same poly-benzimidazole ligand framework have been synthesised and investigated in catecholase activity in acetonitrile medium using 3,5-di-tert-butylcatechol (3,5-DTBC) as a substrate.