A Conductive 2D Conjugated Tetrathia[8]circulene-Based Nickel Metal-Organic Framework for Energy Storage

Herein, a novel D-4 symmetrical redox-active ligand tetrathia[8]circulene-2,3,5,6,8,9,11,12-octaol (8OH-TTC) is designed and synthesized, which coordinates with Ni2+ ions to construct a 2D conductive metal-organic framework (2D c-MOF) named Ni-TTC. Ni-TTC exhibits typical semiconducting properties with electrical conductivity up to approximate to 1.0 S m(-1) at 298 K. Furthermore, magnetism measurements show the paramagnetic property of Ni-TTC with strong antiferromagnetic coupling due to the presence of semiquinone ligand radicals and Ni2+ sites. In virtue of its decent electrical conductivity and good redox activity, the gravimetric capacitance of Ni-TTC is up to 249 F g(-1) at a discharge rate of 0.2 A g(-1), which demonstrates the potential of tetrathia[8]circulene-based redox-active 2D c-MOFs in energy storage applications.