Polymorphism and Superconductivity in Bilayer Molecular Metals (CNB-EDT-TTF)4I3
Salts of the new electron donor cyanobenzene-ethylenedithio-tetrathiafulvalene (CNB-EDT-TTF) were recently described as providing a novel paradigm of two-dimensional conductors with a donor bilayer structure. With triodide anions two different polymorphs (β″ and κ) with the composition (CNB-EDT-TTF)4I3, both with a bilayer structure of the donors were obtained. These polymorphs differ in the packing patterns (β″- and κ-type) of the donor molecules in each layer, in both cases with bifurcated C−N···H interactions effectively coupling head-to-head donor molecules between layer pairs. The β″-polymorphs can be obtained with different degrees of anionic ordering. While the β″ polymorphs remains metallic down to 1.5 K with a ρ300K/ρ4K resistivity ratio of 250, the κ polymorph presents a much smaller resistivity ratio in the range of 4−10 and superconductivity with an onset temperature of 3.5 K.
Contact person: Sandra Rabaça
S. Rabaça, S. Oliveira, I.C. Santos, V. Gama, D. Belo, E.B. Lopes, E. Canadell, M. Almeida, Inorg. Chem. 2016, 55, 10343−10350.
S. Oliveira, D. Belo, I. C. Santos, S. Rabaça, M. Almeida, Beilstein J. Org. Chem. 2015, 11, 951–956.