A family of lanthanide metal-organic frameworks based on a redox-active tetrathiafulvalene-dicarboxylate ligand showing slow relaxation of magnetisation and electronic conductivity

The reaction of the redox-active tetrathiafulvalene ligand and lanthanide ions is an important approach to prepare photo-electro-magnetic multifunctional metal-organic framework materials. A series of isostructural lanthanide metal-organic frameworks (Ln-MOFs) based on the in situ generated tetrathiafulvalene dicarboxylate (TTF-DC) ligand, {[Ln 4 (TTF-DC) 6 (DMF) 4 (H 2 O) 2 ]·4DMF} n (Ln = Gd ( 1-Gd ), Tb ( 1-Tb ), Dy ( 1-Dy ) and Er ( 1-Er )), was synthesized and characterized. These Ln-MOFs display tunable redox-active properties and semiconductor performance, and their electronic conductivities have been significantly improved after oxidation. All MOFs except 2-Tb exhibit slow magnetic relaxation under an applied dc field. 1-Dy and 2-Dy show field-induced single-molecule magnet (SMM) behaviour with energy barriers ( U eff ) of 30.77 K ( τ 0 = 5.23 × 10 −8 ) and 26.41 K (1.04 × 10 −8 s), respectively. Family of isomorphic Ln-MOFs based on redox-active tetrathiafulvalene ligand were synthesized. And their electronic conductivity and slow magnetic relaxation behavior are significantly changed after oxidation.