Luminescent and sustainable d(10) coinage metal thiolate coordination polymers for high-temperature optical sensing

The d(10) coinage metal coordination polymers (CPs) are known to display photophysical properties which can be tuned depending on the functionality of the ligand. Three new CPs made of d(10) coinage metals and methyl thiosalicylate, [M(o-SPhCO(2)Me)](n) (M = Cu, Ag, Au), are reported. They are all constructed from one-dimensional metal-sulfur networks, in which Cu and Ag are three-coordinated to sulfur atoms, whereas Au is only two-coordinated. It results that both Cu(I) and Ag(I) CPs show orange photoemission at room temperature, and the Au(I) one exhibits near-infrared emission at low temperatures. The intense orange-emissive Ag(I) CP and the blue-emissive coumarin 120 have been mixed in an organic matrix, the polyvinylidene fluoride (PVDF), to form a dual luminescent flexible composite film. This film, evaluated for thermometry, shows great sensitivity for temperatures up to 100°C, a temperature never reached with non-lanthanide-based CPs.