Vapochromic and vapoluminescent Zn(II) Schiff- base complexes as chemosensors for volatile organic compounds

Volatile organic compounds (VOCs) play a crucial role in the climate changes because they represent one of the principal atmosphere pollutants.1 For this reason, the fast, selective and quantitative detection of VOCs represents a pivotal asset for preserving the environmental healthiness. Zn(II) Schiff-base complexes are Lewis acidic species having photophysical, vapochromic, vapoluminescent and chemiresistive properties, tuneable through the structure of N2O2 ligand and upon interaction with Lewis bases.2-4 Here, we present a study on the vapochromic and vapoluminescent properties of Zn(II) Schiff-base complexes having different substituents in the salicylidene rings, to develop arrays of chromogenic and fluorogenic chemosensors tailored for the detection of VOCs with Lewis basicity, such as oxygenated VOCs (OVOCs or oxVOCs), nitrogen-containing VOCs (NVOCs), and volatile organic sulphur compounds (VOSCs). In order to develop disposable and low-cost chemosensors, Zn(II) Schiff-base complexes deposited on paper strips were explored. The exposure to VOCs implies different and reversible color and luminescent changes of these paper-based sensors. Therefore, they can be involved for the fabrication of disposable arrays of chromogenic and fluorogenic chemosensors for in-situ detection of VOCs. This research is funded by the University of Catania, PIACERI 2020/2022, Linee di Intervento 2 e 3 and by European Union (NextGeneration EU), through the MUR-PNRR project SAMOTHRACE (ECS00000022).