Facile Transformations of a Binuclear Cp*Co(II) Diamidonaphthalene Complex to Mixed-Valent Co(II)Co(III), Co(III)(μ-H)Co(III), and Co(III)(μ-OH)Co(III) Derivatives

Abstract

A diamido-bridged dicobalt complex supported by a diamidonaphthalene ligand, Cp* 2 Co 2 (μ-1,8-C 10 H 8 (NH) 2 ) (1), was synthesized, and the reactivity relevant to redox transformations of the Co 2 N 2 core was investigated. It was found that the Co(II)− Co(II) bond allows for protonation by [HPPh 3 ][BF 4 ] resulting in a bridging hydride, [1H] + , with pK a ∼ 7.6 in CH 2 Cl 2 . The diamidonaphthalene ligand can stabilize the binuclear system in the Co(II)Co(III) mixed-valent state (1 + ), which is capable of binding CO to afford [1-CO] + . Surprisingly, the mixed-valent complex also activates H 2 O to furnish a Co(III)Co(III) hydroxy complex [1-OH] + accompanied by release of H 2 . The hydroxy ligand in [1-OH] + is exchangeable, as demonstrated by 18 O-labeling experiments on [1-OH] + with H 2 18O that led to the heavier isotopolog [1-18 OH] + .

Computational Exploration of Enzyme Promiscuity: Mechanisms of O2 and NO Reduction Activities of the Desulfovibrio gigas Flavodiiron Protein

“…For several critical intermediates, the principal interaction spin orbital (PISO) analysis for their structures was also performed to deeply uncover the interactions between substrate in Dg_ROO and two iron atoms. PISO analysis is a useful extension of principal interacting orbital (PIO) analysis. , It can decompose the total interactions between two selected fragments into paired orbital interactions for an open-shell system, including a broken-symmetry system. − Here, PISO analysis was carried out using the above-obtained wave functions and the available Python-based code developed by Lin and co-workers, combined with natural population analysis performed by NBO 6.0 package . The isosurfaces of selected real space functions about PISO analysis results were finally rendered by VMD software on the basis of the cube files exported from GaussView 6.0…”

Stepwise Reduction of Redox Noninnocent Nitrosobenzene to Aniline via a Rare Phenylhydroxylamino Intermediate on a Thiolate-Bridged Dicobalt Scaffold

“…In the 1 H NMR spectrum of 6, a diagnostic resonance appears at −6.50 ppm in the high field, which is attributed to the proton on the bridging hydroxide. 41 Additionally, the corresponding absorption peak for the O−H stretching vibration appeared at 3550 cm −1 . Except for cobalt complex 6, the concomitant organic compound was determined as PhNH 2 by gas chromatography−mass spectrometry (GC− MS) analysis, and its yield was estimated to be 47% by GC analysis.…”

The strongin vitroandvivocytotoxicity of three new cobalt(ii) complexes with 8-methoxyquinoline

“…4,5 In addition, cobalt (Co) is an essential element for life, and the study of Co( ii / iii ) coordination compounds for biological and medical applications has flourished more recently. 6 These activated Co( ii / iii ) complexes include hydroxamatocobalt( ii ) complexes, 7 salicylaldehyde-derivative copper( ii ) complexes, 8 phen-dicarboxylic acid based cobalt( ii ) antitumor drugs, 9 cobalt( ii ) oxoisoaporphine complexes, 10 2-benzimidazolyl-pyridine copper( ii ) complexes, 11 thiosemicarbazone cobalt( ii ) complexes, 1 a ,12 diamidonaphthalene cobalt( ii ) complexes, 13 cobalt dioxolene/isonicotinic compounds, 14 tris(2-pyridylmethyl)amine cobalt pro-drugs, 15 cobalt( ii ) pyridyl complexes, 16 and anthraquinone-type cobalt complexes. 17…”

“…4,5 In addition, cobalt (Co) is an essential element for life, and the study of Co(II/III) coordination compounds for biological and medical applications has flourished more recently. 6 These activated Co(II/III) complexes include hydroxamatocobalt(II) complexes, 7 salicylaldehyde-derivative copper(II) complexes, 8 phen-dicarboxylic acid based cobalt(II) antitumor drugs, 9 cobalt(II) oxoisoaporphine complexes, 10 2-benzimidazolyl-pyridine copper(II) complexes, 11 thiosemicarbazone cobalt(II) complexes, 1a,12 diamidonaphthalene cobalt (II) complexes, 13 cobalt dioxolene/isonicotinic compounds, 14 tris(2-pyridylmethyl)amine cobalt pro-drugs, 15 cobalt(II) pyridyl complexes, 16 and anthraquinone-type cobalt complexes. 17 Many different metal 8-hydroxyquinoline derived compounds can function as important DNA inhibitors, 18 protein synthesis inhibitors, 19 amyloid-β (Aβ) oligomer drugs, 20 photosensitizers, 21 mitochondrial apoptosis related antineoplastic agents, 22 bFGF-mediated angiogenesis specific inhibitors, 23 topoisomerase IIa inhibitors, 24 telomerase inhibitors, 25 cell autophagy inductors, 26 and so on.…”