Recent research on the mechanochemistry of metallocene mechanophores has shed light on the force-responsiveness of these thermally and chemically stable organometallic compounds. In this work, we report a combination of experimental and computational studies on the mechanochemistry of main-chain cobaltocenium-containing polymers. Ester derivatives of the cationic cobaltocenium, though isoelectronic to neutral ferrocene, are unstable in the nonmechanical control experimental conditions that were accommodated by their ferrocene analogs. Replacing the electron withdrawing C-ester linkages with electron-donating C-alkyls conferred the necessary stability and enabled the mechanochemistry of the cobaltocenium to be assessed. Despite their high bond dissociation energy, cobaltocenium mechanophores are found to be selective sites of main chain scission under sonomechanical activation. Computational CoGEF calculations suggest that the presence of a counterion to cobaltocenium plays a vital role by promoting a peeling mechanism of dissociation in conjunction with the initial slipping.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jacs.1c05233 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Cobaltocene-Mediated Catalytic Hydride Transfer: Strategies for Electrocatalytic Hydrogenation.
J Am Chem Soc
June 2024
Department of Chemistry, Stanford University, Stanford, California 94306, United States.
The selective electrocatalytic hydrogenation of organics with transition metal hydrides is a promising strategy for electrosynthesis and energy storage. We report the electrocatalytic hydrogenation of acetone with a cyclopentadienone-iridium complex in a tandem electrocatalytic cycle with a cobaltocene mediator. The reductive protonation of cobaltocenium with mild acids generates (CH)Co(CH) (CpCo(CpH)), which functions as an electrocatalytic hydride mediator to deliver a hydride to cationic Ir(III) without generating hydrogen.
View Article and Find Full Text PDFStability Trends in disubstituted Cobaltocenium Based on the Analysis of the Machine Learning Models.
J Phys Chem A
December 2023
Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States.
Cobaltocenium derivatives have shown great potential as components of anion exchange membranes in fuel cells because they exhibit excellent thermal and alkaline stability under operating conditions while allowing for high anion mobility. The properties of the cobaltocenium-anion complexes can be chemically tuned through the substituent groups on the cyclopentadienyl (Cp) rings of the cation CoCp. However, the synthesis and characterization of the full range of possible derivatives are very challenging and time-consuming, and while the computational tools can greatly expedite this process, full screening of the electronic structure at a high level of theory is still computationally intensive.
View Article and Find Full Text PDFTheoretical Examination of the Hydroxide Transport in Cobaltocenium-Containing Polyelectrolytes.
J Phys Chem B
November 2023
Department of Chemistry & Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States.
Polymers incorporating cobaltocenium groups have received attention as promising components of anion-exchange membranes (AEMs), exhibiting a good balance of chemical stability and high ionic conductivity. In this work, we analyze the hydroxide diffusion in the presence of cobaltocenium cations in an aqueous environment based on the molecular dynamics of model systems confined in one dimension to mimic the AEM channels. In order to describe the proton hopping mechanism, the forces are obtained from the electronic structure computed at the density-functional tight-binding level.
View Article and Find Full Text PDFFerrocene/ferrocenium, cobaltocene/cobaltocenium and nickelocene/nickelocenium: from gas phase ionization energy to one-electron reduction potential in solvated medium.
Phys Chem Chem Phys
June 2023
Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
We propose a theoretical procedure for accurate determination of reduction potentials for three metallocene couples, CpM/CpM, where M = Fe, Co and Ni. This procedure first computes the gas phase ionization energy (IE) using the explicitly correlated CCSD(T)-F12 method and includes the zero-point energy correction, core-valence electronic correlation, and relativistic and spin-orbit coupling effects. By means of Born-Haber thermochemical cycle, the one-electron reduction potential is obtained as the sum of the gas phase IE and the corresponding Gibbs free energies of solvation (Δ) for both the neutral and cationic species.
View Article and Find Full Text PDFPartially fluorinated poly(arylene-alkane)s containing cobaltocenium for alkaline-stable anion exchange membranes.
Chem Commun (Camb)
April 2023
Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China.
Alkali-resistant metal-based cationic polyelectrolytes are designed as anion exchange membranes. After grafting aminocobaltocene hexafluorophosphates onto partially fluorinated ether-free poly(arylene-alkane)s a simple nucleophilic substitution reaction, the membrane exhibits excellent chemical, thermal and mechanical stability, high hydroxide conductivity, as well as durability of single cells for 400 h.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!