Redox Activity and Two-Step Valence Tautomerism in a Family of Dinuclear Cobalt Complexes with a Spiroconjugated Bis(dioxolene) Ligand

2013 ◽  
Vol 135 (22) ◽  
pp. 8304-8323 ◽  
Author(s):  
Kerwyn G. Alley ◽  
Giordano Poneti ◽  
Peter S. D. Robinson ◽  
Ayman Nafady ◽  
Boujemaa Moubaraki ◽  
...  
Keyword(s):  
Cobalt Complexes ◽  
Redox Activity ◽  
Valence Tautomerism

scholarly journals Rich Redox-Activity and Solvatochromism in a Family of Heteroleptic Cobalt Complexes

2021 ◽  
Author(s):  
Vincent L. Nadurata ◽  
Moya Hay ◽  
Jett Tao Janetzki ◽  
Gemma Kate Gransbury ◽  
Colette Boskovic
Keyword(s):  
Charge Transfer ◽  
Cobalt Complexes ◽  
Redox Activity ◽  
Redox Active Ligands ◽  
Valence Tautomerism ◽  
Redox Active ◽  
Active Metal ◽  
Metal Redox ◽  
Redox Active Metal

The combination of redox-active metals with redox-active ligands can lead to interesting charge transfer behaviours, including valence tautomerism and solvatochromism. With the aim of investigating a relatively underexplored redox-active metal/redox-active...

Exploring ligand non-innocence of coordinatively-versatile diamidodipyrrinato cobalt complexes

2019 ◽  
Vol 55 (12) ◽  
pp. 1825-1828 ◽  
Author(s):  
Simran S. Saund ◽  
Samantha L. Goldschmid ◽  
Karina Ng ◽  
Veronica Stewart ◽  
Maxime A. Siegler ◽  
...  
Keyword(s):  
Cobalt Complexes ◽  
Redox Activity ◽  
Coordination Modes ◽  
New Strategy ◽  
Metal Ligand

A new strategy is reported for modifying the redox activity of diamidodipyrrins through coordination modes in the same metal–ligand platform.

Controlling Valence Tautomerism of Cobalt Complexes Containing the Benzosemiquinone Anion as Ligand

1993 ◽  
Vol 32 (6) ◽  
pp. 880-882 ◽  
Author(s):  
David M. Adams ◽  
Andrea Dei ◽  
Arnold L. Rheingold ◽  
David N. Hendrickson
Keyword(s):  
Cobalt Complexes ◽  
Valence Tautomerism

Theoretical Study of the Mechanism of Valence Tautomerism in Cobalt Complexes

2010 ◽  
Vol 114 (49) ◽  
pp. 12928-12935 ◽  
Author(s):  
Daisuke Sato ◽  
Yoshihito Shiota ◽  
Gergely Juhász ◽  
Kazunari Yoshizawa
Keyword(s):  
Theoretical Study ◽  
Cobalt Complexes ◽  
Valence Tautomerism

Toward a Comprehensive Treatment of Tautomerism in Chemoinformatics Including in InChI V2

2019 ◽  
Author(s):  
Devendra K. Dhaked ◽  
Wolf Ihlenfeldt ◽  
Hitesh Patel ◽  
Marc Nicklaus
Keyword(s):  
Small Molecule ◽  
Comprehensive Treatment ◽  
Experimental Literature ◽  
Web Tool ◽  
Valence Tautomerism ◽  
Standard Version ◽  
Small Molecule Databases

<p>We have collected 86 different transforms of tautomeric interconversions. Out of those, 54 are for prototropic (non-ring-chain) tautomerism; 21 for ring-chain tautomerism; and 11 for valence tautomerism. The majority of these rules have been extracted from experimental literature. Twenty rules – covering the most well-known types of tautomerism such as keto-enol tautomerism – were taken from the default handling of tautomerism by the chemoinformatics toolkit CACTVS. The rules were analyzed against nine differerent databases totaling over 400 million (non-unique) structures as to their occurrence rates, mutual overlap in coverage, and recapitulation of the rules’ enumerated tautomer sets by InChI V.1.05, both in InChI’s Standard and a Non-Standard version with the increased tautomer-handling options 15T and KET turned on. These results and the background of this study are discussed in the context of the IUPAC InChI Project tasked with the redesign of handling of tautomerism for an InChI version 2. Applying the rules presented in this paper would approximately triple the number of compounds in typical small-molecule databases that would be affected by tautomeric interconversion by InChI V2. A web tool has been created to test these rules at https://cactus.nci.nih.gov/tautomerizer.</p>

Cobaloxime-Based Double Complex Salts as Efficient and Versatile Catalysts for the Light-Driven Hydrogen Evolution Reaction

2020 ◽  
Author(s):  
Elisabeth Hofmeister ◽  
Jisoo Woo ◽  
Tobias Ullrich ◽  
Lydia Petermann ◽  
Kevin Hanus ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Systematic Study ◽  
Cobalt Complexes ◽  
Spectroscopic Studies ◽  
Double Complex ◽  
Double Complex Salts ◽  
Noble Metal Catalysts ◽  
Reduction Potentials ◽  
Complex Salts

Cobaloximes and their BF<sub>2</sub>-bridged analogues have emerged as promising non-noble metal catalysts for the photocatalytic hydrogen evolution reaction (HER). Herein we report the serendipitous discovery that double complex salts such as [Co(dmgh)<sub>2</sub>py<sub>2</sub>]<sup>+</sup>[Co(dmgBPh<sub>2</sub>)<sub>2</sub>Cl<sub>2</sub>]<sup>-</sup> can be obtained in good yields by treatment of commercially available [Co(dmgh)<sub>2</sub>pyCl] with triarylboranes. A systematic study on the use of such double complex salts and their single salts with simple counterions as photocatalysts revealed HER activities comparable or superior to existing cobaloxime catalysts and suggests ample opportunities for this compound class in catalyst/photosensitizer dyads and immobilized architectures. Preliminary electrochemical and spectroscopic studies indicate that one key advantage of these charged cobalt complexes is that the reduction potentials as well as the electrostatic interaction with charged photosensitizers can be tuned.

Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding

2019 ◽  
Author(s):  
Andrew Rosen ◽  
M. Rasel Mian ◽  
Timur Islamoglu ◽  
Haoyuan Chen ◽  
Omar Farha ◽  
...  
Keyword(s):  
Density Functional ◽  
Metal Organic Frameworks ◽  
Redox Activity ◽  
Screening Methods ◽  
Bridging Ligands ◽  
Metal Centers ◽  
Computational Screening ◽  
Open Metal Sites ◽  
Metal Organic ◽  
Unsaturated Metal Sites

<p>Metal−organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability to selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O<sub>2</sub> and N<sub>2</sub> adsorption at the coordinatively unsaturated metal sites of several MOF families. A variety of design handles are identified that can be used to modify the redox activity of the metal centers, including changing the functionalization of the linkers (replacing oxido donors with sulfido donors), anion exchange of bridging ligands (considering μ-Br<sup>-</sup>, μ-Cl<sup>-</sup>, μ-F<sup>-</sup>, μ-SH<sup>-</sup>, or μ-OH<sup>-</sup> groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O<sub>2</sub> affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O<sub>2</sub>. In contrast with O<sub>2</sub> adsorption, N<sub>2</sub> adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V<sup>2+</sup> open metal sites. As one example from the screening study, we predict that exchanging the μ-Cl<sup>-</sup> ligands of M<sub>2</sub>Cl<sub>2</sub>(BBTA) (H<sub>2</sub>BBTA = 1<i>H</i>,5<i>H</i>-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH<sup>-</sup> groups would significantly enhance the strength of O<sub>2</sub> adsorption at the open metal sites without a corresponding increase in the N<sub>2</sub> affinity. Experimental investigation of Co<sub>2</sub>Cl<sub>2</sub>(BBTA) and Co<sub>2</sub>(OH)<sub>2</sub>(BBTA) confirms that the former exhibits only weak physisorption, whereas the latter is capable of chemisorbing O<sub>2</sub> at room temperature. The chemisorption behavior is attributed to the greater electron-donating character of the μ-OH<sup>-</sup><sub> </sub>ligands and the presence of H-bonding interactions between the μ-OH<sup>-</sup> bridging ligands and the O<sub>2</sub> adsorbate.</p>

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