Photocurrent responsive supramolecular coordination networks with redox-active tetrathiafulvalene cores

Abstract

Redox-active tetrathiafulvalene (TTF) is key building block to construct multifunctional metal-organic complex materials. Herein three TTF-based supramolecular coordination networks, [Cu2(L)2(bpy)2]n(1) and M2(L)2(bpy)2(H2O)4 (M = Co2+ (2), Ni2+ (3)) (L = dimethylthio-tetrathiafulvalene-bisthiol-benzoate, bpy = 2,2’-bipyridine), were prepared by using solvothermal method and characterized by single-crystal X-ray analyses. Complex 1 displays a one-dimensional (1D) coordination polymer with chain structure, which further linked by S···S interactions to form a 3D supramolecular network. Complexes 2 and 3 are isostructures and show dinuclear metallic compound with two μ2-H2O bridges, which finally exhibit 3D supramolecular networks supported by both of hydrogen bonds and S···S interactions. The electrochemical properties of compound 1–3 were investigated by cyclic voltammetry using surface-modified electrodes, and the results revealed that 1–3 are photocurrent responsive materials and the metal coordination centers seem to have no obvious effect on the photocurrent response.