A Metal–Organic Framework Based on a Nickel Bis(dithiolene) Connector: Synthesis, Crystal Structure, and Application as an Electrochemical Glucose Sensor

Functionalizing the redox-active tetrathiafulvalene (TTF) core with groups capable of coordination to metals provides new perspectives on the modulation of architectures and electronic properties of organic–inorganic hybrid materials. With a view to extending this concept, we have now synthesized nickel bis(dithiolene-dibenzoic acid), [Ni(C 2 S 2 (C 6 H 4 COOH) 2 ) 2 ], which can be considered as the inorganic analogue of the organic tetrathiafulvalene-tetrabenzoic acid (H 4 TTFTB). Likewise, [Ni(C 2 S 2 (C 6 H 4 COOH) 2 ) 2 ] is a redox-active linker for new functional metal–organic frameworks, as demonstrated here with the synthesis of [Mn 2 {Ni(C 2 S 2 (C 6 H 4 COO) 2 ) 2 }(H 2 O) 2 ]·2DMF, ( 1, DMF = N,N -dimethylformamide). 1 is isomorphic to the reported [Mn 2 (TTFTB)(H 2 O) 2 ] ( 2 ) but is a better electrochemical glucose sensor due to the multiple oxidation–reduction states of the [NiS 4 ] core, which allow glucose to be oxidized to glucolactone by the high oxidation state [NiS 4 ] center. As a non-enzymatic glucose sensor, 1 on Cu foam ( CF ), 1-CF, was synthesized by a one-step hydrothermal method and exhibited an excellent electrochemical performance. The fabricated 1-CF electrode offers a high sensitivity of 27.9 A M –1 cm –2, with a wide linear detection range from 2.0 × 10 –6 to 2.0 × 10 –3 M, a low detection limit of 1.0 × 10 –7 M (signal/noise = 3), and satisfactory stability and reproducibility.