In this study we report a strategy to attach methylimidazolium fragments as ionic liquid units on an established iron porphyrin catalyst for the selective reduction of CO2 to CO in water, precluding the need for external proton source.
In his pioneering work to unravel the catalytic power of enzymes, Warshel has pertinently validated that electrostatic interactions play a major role in the activation of substrates. Implementing such chemical artifice in molecular catalysts may help improve their catalytic properties. In this study, a series of tetra‐, di‐, and mono‐substituted iron porphyrins with cationic imidazolium groups were designed. Their presence in the second coordination sphere helped stabilize the [Fe−CO2] intermediate through electrostatic interactions. It was found herein that the electrocatalytic overpotential is a function of the number of embarked imidazolium. Importantly, a gain of six orders of magnitude in turnover frequencies was observed going from a tetra‐ to a mono‐substituted catalyst. Furthermore, the comparative study showed that catalytic performances trend of through‐space electrostatic interaction, a first topological effect reported for iron porphyrins, outperforms the classical through‐structure electronic effect.
In this paper the authors propose a new distributed double guided hybrid algorithm combining the particle swarm optimization (PSO) with genetic algorithms (GA) to resolve maximal constraint satisfaction problems (Max-CSPs). It consists on a multi-agent approach inspired by a centralized version of hybrid algorithm called Genetical Swarm Optimization (GSO). Their approach consists of a set of evolutionary agents dynamically created and cooperating in order to find an optimal solution. Each agent executes its own hybrid algorithm and it is able to compute its own parameters. The authors' approach is compared to the GSO. It demonstrates its superiority. They reached these results thanks to the distribution using multi-agent systems, diversification and intensification mechanisms.
The Cover Feature shows an electrostatic‐assisted catalysis of carbon dioxide molecule at an iron porphyrin decorated with cationic functions in the second coordination sphere. Such functions significantly lower the overpotential of the reaction while maintaining high catalytic efficiency. This provides a new way to vault the reactivity pattern of molecular catalysts. More information can be found in the Full Paper by A. Khadhraoui et al.
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