Crystal structure and metallization mechanism of the π-radical metal TED
| Autor: | Kunie Ishioka, Samantha N. Hood, Yoshitaka Matsushita, Kazuto Hirata, Hui Yang, Yuka Kobayashi, Aron Walsh |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Chemical Science |
| Popis: | Radical electrons tend to localize on individual molecules, resulting in an insulating (Mott–Hubbard) bandgap in the solid state. Herein, we report the crystal structure and intrinsic electronic properties of the first single crystal of a π-radical metal, tetrathiafulvalene-extended dicarboxylate (TED). The electrical conductivity is up to 30 000 S cm−1 at 2 K and 2300 S cm−1 at room temperature. Temperature dependence of resistivity obeys a T3 power-law above T > 100 K, indicating a new type of metal. X-ray crystallographic analysis clarifies the planar TED molecule, with a symmetric intramolecular hydrogen bond, is stacked along longitudinal (the a-axis) and transverse (the b-axis) directions. The π-orbitals are distributed to avoid strong local interactions. First-principles electronic calculations reveal the origin of the metallization giving rise to a wide bandwidth exceeding 1 eV near the Fermi level. TED demonstrates the effect of two-dimensional stacking of π-orbitals on electron delocalization, where a high carrier mobility of 31.6 cm2 V−1 s−1 (113 K) is achieved. The molecular arrangement that enables metallic conduction in a single-component pure organic crystal is revealed by single-crystal X-ray diffraction. |
| Databáze: | OpenAIRE |
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