Kinetics and Thermodynamics of Constitutional Dynamic Coordination Systems Based on Fe II , Co II , Ni II , Cu II , and Zn II

Simultaneous CO2 capture and metal purification from waste streams using triple-level dynamic combinatorial chemistry

A reduction in CO₂ emissions is required to mitigate global warming. Post-combustion carbon capture is one of the most developed technologies that has the potential to meet this goal, but its cost prevents its widespread use. A different approach would be to use CO₂ directly as it is captured, before it is stored. Here we explore spontaneous CO₂ fixation by industrial polyamines as a strategy to generate dynamic libraries of ligands for metal separation and recovery. We identify the CO₂ loadings and solvents promoting the optimal precipitation of each metal from the dynamic libraries of complexes. We demonstrate the separation of lanthanum and nickel using the exhaust gas of an internal combustion engine vehicle, and show that the three metal constituents of the La₂Ni₉Co alloys used to manufacture the batteries of electric vehicles can be separated and recovered by successive CO₂-induced selective precipitations. Beyond the concept of CO₂-sourced multi-level dynamic coordination chemistry, this study provides a potential framework for integrated CO₂ capture and use through sustainable processes.

Design, Synthesis and Self-Assembly of Functional Amphiphilic Metallodendrimers

A new family of alkynylated, amphiphilic dendrimers consisting of amidoamine linkers connected to 5,5'-functionalized 2,2'-bipyridine cores has been developed and evaluated in the formation of metallodendrimers of different generations and in self-assembly protocols. A convergent synthetic strategy was applied to provide dumbbell-shaped amphiphilic dendrimers, where the 2,2'-bipyridine cores could be coordinated to FeII centers to afford corresponding metallodendrimers. The ability of the metallic- and non-metallic dendritic structures to self-assemble into functional supramolecular aggregates were furthermore evaluated in aqueous solution. Spherical aggregates with sizes of a few hundred nanometers were generally produced, where controlled disassembly of the metallodendrimers through decomplexation could be achieved.