Redox-active ligands: Recent advances towards their incorporation into coordination polymers and metal-organic frameworks

Electrocatalytic CO2Reduction: from Discrete Molecular Catalysts to Their Integrated Catalytic Materials

“…Taking a recent breakthrough as an example, considering the fact that the Cu(II) ion prefers to adopt a square-planar coordination geometry, while Cu(I) prefers a square-pyramidal geometry, [68] a copper complex supported by benzotriazolebased ligands was constructed as a robust electrocatalyst (Cu-MFU-4 l, Figure 5) to achieve the high-performance (FE CH4 = 92 %) of methane electrosynthesis from ECR. Remarkably, the electrocatalyst exhibited surprisingly high stabilization without degradation even at as low as À 1.3 V (vs. RHE), [69] which might be rationalized by the combined contributions: i) during ECR, the Cu center remains in square-pyramidal ligand-binding geometry thermodynamically favorable for the stabilization of Cu(I) ion; ii) the electroacquired electron density is largely delocalized onto the redox-active benzotriazole ligand scaffolds, [70] thereby preventing the reductive stripping of copper ion. It is worth mentioning that this is the only copper complex catalyst for beyond 2e À reduction products from ECR (relatively negative applied potential is usually necessary) so far, evidenced to be stable (without demetalization) by in situ XAS characterization.…”

Redox-active benzoquinones as challenging “non-innocent” linkers to construct 2D frameworks and nanostructures with tunable physical properties

“…Several reviews are reported on CPs and MOFs formed by redox-active linkers and nodes, 26,71–76 evidencing the crucial role of redox-activity on their physical properties and applications. The present review covers up new insights on benzoquinones (BQ)-based 2D CPs/MOFs and nanostructures over the last decade, highlighting the extreme versatility of this class of redox-active linkers in tailoring the physical properties of 2D frameworks and the related applications.…”

Redox-Hopping-Based Charge Transport Mediated by Ru(II)-Polypyridyl Species Immobilized in a Mesoporous Metal-Organic Framework

“…Additionally, the fixed spatial separation of consecutive linker-or node-sited/ grafted catalysts can delimit catalyst de-activation by dimerization or aggregation. MOFs can be made redox-active either by judiciously chosen redox-active organic linkers or redox-active metal nodes (Kung et al, 2020;Ding et al, 2021). Alternatively, they can be rendered redox-active by post-synthetic incorporation of redox-active species-for example, by chemically grafting and tethering to otherwise inactive nodes (Hod et al, 2015b;Celis-Salazar et al, 2019).…”