Facile synthesis, precise species control and chemical transformation of highly conducting organic metal chalcogenides CuxBHT (x=3, 4, 5.5)

The design of conducting organic metal chalcogenides (OMCs) has attracted extensive attention for their applications in diverse areas. However, only a handful of OMCs exhibit appealing electrical transport properties due to the limited synthetic approaches. Herein, a facile and controllable synthetic approach for the preparation of highly crystalline benzenehexathiol (BHT)-based OMCs using Cu2O as a precursor is reported. Under heterogeneous conditions, a series of highly conducting organic metal chalcogenides CuxBHT (x = 3, 4, and 5.5) were precisely constructed via variation of the molar ratio between Cu2O and BHT. In particular, a fascinating chemical transformation phenomenon was discovered in this work. This is the first time that a phase transition has been observed in conducting OMCs, with the semiconducting species (Cu4BHT and Cu5.5BHT) being converted to metallic species (Cu3BHT) under delicate oxidation regulation. This work provides a prominent paradigm for constructing highly crystalline OMCs, and opens up the possibility of developing OMCs with different structural topologies through chemical transformation.