A semiconducting gyroidal metal-sulfur framework for chemiresistive sensing

The gyroid is an iconic structure that conjures up an intriguing 3D congener of the famous electronic systems of graphene and related 2D materials. Unlike the more accessible 2D graphitic systems, gyroidal metal-organic frameworks with demonstrated conductive properties remain unknown. We here report a semiconducting gyroidal net (denoted as HTT-Pb) that derives its rich electronic properties from the large organic pi-electron system of a triphenylene core, highly polarizable Pb-dithiolene links, and robust Pb-oxo connections. In contrast to the generally encountered difficulty in crystallizing metal-thiolate networks, single crystals of HTT-Pb amenable to X-ray studies can be reliably obtained by regular solvothermal synthesis. The electronic conductivity of the framework solid is highly responsive to the water content in air, demonstrating potential use in chemiresistive sensing of humidity.