Redox-Active Metal-Organic Frameworks with Three-Dimensional Lattice Containing the m -Tetrathiafulvalene-Tetrabenzoate.

Metal-organic frameworks (MOFs) constructed by tetrathiafulvalene-tetrabenzoate (H 4 TTFTB) have been widely studied in porous materials, while the studies of other TTFTB derivatives are rare. Herein, the meta derivative of the frequently used p -H 4 TTFTB ligand, m -H 4 TTFTB, and lanthanide (Ln) metal ions (Tb 3+ , Er 3+ , and Gd 3+ ) were assembled into three novel MOFs. Compared with the reported porous Ln-TTFTB, the resulted three-dimensional frameworks, Ln- m -TTFTB ([Ln 2 ( m -TTFTB)( m -H 2 TTFTB) 0.5 (HCOO)(DMF)]·2DMF·3H 2 O), possess a more dense stacking which leads to scarce porosity. The solid-state cyclic voltammetry studies revealed that these MOFs show similar redox activity with two reversible one-electron processes at 0.21 and 0.48 V (vs. Fc/Fc + ). The results of magnetic properties suggested Dy- m -TTFTB and Er- m -TTFTB exhibit slow relaxation of the magnetization. Porosity was not found in these materials, which is probably due to the meta-configuration of the m -TTFTB ligand that seems to hinder the formation of pores. However, the m -TTFTB ligand has shown to be promising to construct redox-active or electrically conductive MOFs in future work.