A photoswitchable ligand and PdII combine to form a [Pd2
4]4+ coordination cage. The photoswitching selectivity towards the metastable isomer is significantly improved when coordinated, allowing near-quantitatively photoswitching to a new species, [PdL
2]2+. This new species stabilizes the metastable isomer, increasing the thermal half-life compared to the free ligand.
A photoswitchable ligand based on azobenzene is self-assembled with palladium(II) ions to form a [Pd2(E-L)4]4+ cage. Irradiation with 470 nm light results in the near-quantitative switching to a monomeric species [Pd(Z-L)2]2+, which can be reversed by irradiation with 405 nm light, or heat. The photoswitching selectivity towards the metastable isomer is significantly improved upon self-assembly, and the thermal half-life is extended from 40 days to 850 days, a promising approach for tuning photoswitching properties.Zum Volltext