Bioorthogonal chemistry has enabled scientists to carry out controlled chemical processes in high yields in vivo while minimizing hazardous effects. Its extension to the field of polyoxometalates (POMs) could open up new possibilities and new applications in molecular electronics, sensing and catalysis, including inside living cells. However, this comes with many challenges that need to be addressed to effectively implement and exploit bioorthogonal reactions in the chemistry of POMs. In particular, how to protect POMs from the biological environment but make their reactivity selective towards specific bioorthogonal tags (and thereby reduce their toxicity), as well as which bioorthogonal chemistry protocols are suitable for POMs and how reactions can be carried out are questions that we are exploring herein. This perspective conceptualizes and discusses advances in the supramolecular chemistry of POMs, their click chemistry, and POM-based surface engineering to develop innovative bioorthogonal approaches tailored to POMs and to improve POM biological tolerance.

A set of alkynyl-tris(2-pyridyl)phosphine Au(I) complexes was synthesized and characterized. Free coordination functions on the ligand environment periphery, namely ‘scorpionate’ PPy₃ and the CC bond, allowed these ditopic metalloligands to be selectively linked to 1D coordination polymers by reaction with Cu(I), which used both Cu–(N-PPy₃) and Cu–(η²-CC) coordination modes. Single-crystal and powder XRD, NMR, and XPS techniques were used to characterize the coordination polymers obtained. Heterobimetallic Au(I)–Cu(I) coordination polymers demonstrate triplet photoluminescence which was studied by spectroscopic and computational methods to understand the pathway of energy transfer inside the chain of linked chromophore centres. The intriguing feature of the electronic structure of heterobimetallic supramolecular assemblies is the ‘long-distance’ electronic transition involving PhC₂ and PPy₃ ligands located at a distance of more than 1 nm from each other. Thus, the assembly of a heterobimetallic coordination polymer from relatively simple ‘building blocks’ retains the block-wise nature of the electronic structure, but the photophysical properties of the polymer are fundamentally different from the properties of discrete organometallic components.