Selective, robust and cost-effective chemical sensors for detecting small volatile-organic compounds (VOCs) have widespread applications in industry, healthcare and environmental monitoring. Here we design a Pt(II) pincer-Type material with selective absorptive and emissive responses to methanol and water. The yellow anhydrous form converts reversibly on a subsecond timescale to a red hydrate in the presence of parts-per-Thousand levels of atmospheric water vapour. Exposure to methanol induces a similarly-rapid and reversible colour change to a blue methanol solvate. Stable smart coatings on glass demonstrate robust switching over 104 cycles, and flexible microporous polymer membranes incorporating microcrystals of the complex show identical vapochromic behaviour. The rapid vapochromic response can be rationalised from the crystal structure, and in combination with quantum-chemical modelling, we provide a complete microscopic picture of the switching mechanism. We discuss how this multiscale design approach can be used to obtain new compounds with tailored VOC selectivity and spectral responses.
Bibliographical noteFunding Information:
JMS is grateful for helpful discussions with Rachel Crespo-Otero regarding the molecular quantum-chemical calculations. This work was primarily supported by a UK Engineering and Physical Sciences Research Council (EPSRC) Programme Grant (grant no. EP/ K004956/1). The project also benefited from support from EPSRC grant no. EP/I01974X. SF is grateful for the support of a fellowship from the European Commission, under the Marie Curie Intra-European Fellowship scheme (PIEF-GA-2009-252883; SFL-PRR). The computational modelling was primarily carried out on the Archer high-performance computing facility, accessed through membership of the UK Materials Chemistry Consortium, which is funded by EPSRC grant no. EP/L000202. We also made use of the SiSu supercomputer at the IT Center for Science (CSC), Finland, via the Partnership for Advanced Computing in Europe (PRACE) project no. 13DECI0317/IsoSwitch. Some calculations were also performed on the Balena facility at the University of Bath, which is maintained by Bath University Computing Services. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under Contract No. DE-AC02-05CH11231. We also thank Dr Robin Owen for the use of the spectrometer on Beamline I24 of the Diamond Light Source facility.
© 2017 The Author(s).