A Bioinspired Zn^II/Fe^III Heterobimetallic Catalyst for Thia-Michael Addition

A novel tetranuclear Zn^II/Fe^III heterobimetallic complex was synthesized, and the complex can efficiently catalyze the Michael addition of thiophenols to α,β-unsaturated enones, even for tertiary carbon–sulfur bond formation

A Bioinspired Zn^II/Fe^III Heterobimetallic Catalyst for Thia-Michael Addition

A novel tetranuclear Zn^II/Fe^III heterobimetallic complex was synthesized, and the complex can efficiently catalyze the Michael addition of thiophenols to α,β-unsaturated enones, even for tertiary carbon–sulfur bond formation

Ambient Stable Trigonal Bipyramidal Copper(III) Complexes Equipped with an Exchangeable Axial Ligand

A stable trigonal bipyramidal copper­(III) complex, [PPN]­[Cu­(^TMSPS3)­Cl] (<b>1</b>, wherein PPN represents bis­(triphenylphosphine)­iminium), was synthesized from CuCl₂/PPNCl via intramolecular copper­(II) disproportionation. Under ambient conditions, the axial chloride of <b>1</b> is exchangeable in solution thus making <b>1</b> serve as an intermediate to prepare trigonal bipyramidal copper­(III) derivatives, e.g., [PPN]­[Cu­(^TMSPS3)­(N₃)] (<b>2</b>) and [Cu­(^TMSPS3)­(DABCO)] (<b>3</b>). Diamagnetic complexes <b>1</b>–<b>3</b> were fully characterized by X-ray crystallography, NMR, UV–vis, and Cu K-edge absorption spectroscopy. A series of UV–vis titrations were performed to investigate the relative ligand affinity toward the [Cu­(^TMSPS3)] moiety, verifying the 1:1 binding equilibrium between various ligands. Compared to known copper­(III) compounds, Cu K-edge absorptions of <b>1</b>–<b>3</b> possess lower pre-edge energy and higher shakedown transition energy, which, respectively, attribute to the electron donation from ^TMSPS3^3– ligand and their trigonal ligand field

A Structurally Characterized Nonheme Cobalt–Hydroperoxo Complex Derived from Its Superoxo Intermediate via Hydrogen Atom Abstraction

Bubbling O₂ into a THF solution of Co^II(BDPP) (<b>1</b>) at −90 °C generates an O₂ adduct, Co­(BDPP)­(O₂) (<b>3</b>). The resonance Raman and EPR investigations reveal that <b>3</b> contains a low spin cobalt­(III) ion bound to a superoxo ligand. Significantly, at −90 °C, <b>3</b> can react with 2,2,6,6-tetramethyl-1-hydroxypiperidine (TEMPOH) to form a structurally characterized cobalt­(III)-hydroperoxo complex, Co^III(BDPP)­(OOH) (<b>4</b>) and TEMPO^•. Our findings show that cobalt­(III)-superoxo species are capable of performing hydrogen atom abstraction processes. Such a stepwise O₂-activating process helps to rationalize cobalt-catalyzed aerobic oxidations and sheds light on the possible mechanism of action for Co-bleomycin