Novel ET-Coordinated Copper(I) Complexes: Syntheses, Structures, and Physical Properties (ET = BEDT-TTF = Bis(ethylenedithio)tetrathiafulvalene)
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- 作者：Ryo Kanehama ; Masamichi Umemiya ; Fumiyasu Iwahori ; Hitoshi Miyasaka ; Ken-ichi Sugiura ; Masahiro Yamashita ; Yasukata Yokochi ; Hiroshi Ito ; Shin-ichi Kuroda ; Hideo Kishida ; and Hiroshi Okamoto
- 刊名：Inorganic Chemistry
- 出版年：2003
- 出版时间：November 3, 2003
- 年：2003
- 卷：42
- 期：22
- 页码：7173 - 7181
- 全文大小：367K
- 年卷期：v.42,no.22(November 3, 2003)
- ISSN：1520-510X
文摘
New molecular charge-transfer complexes of bis(ethylenedithio)tetrathiafulvalene (ET), (ET)Cu2Br4 (1), (ET)2Cu6Br10 (2), (ET)2[Cu4Br6ET] (3), (ET)2Cu2Br4 (4), (ET)2Cu3Br7(H2O) (5), and (ET)2Cu6Br10(H2O)2 (6), have been synthesizedby diffusing reaction of ET and CuIIBr2. Their crystal structures and physical properties have been investigated.X-ray analyses revealed that ET molecules coordinated to the copper ions with the sulfur atoms of the ethylenedithiogroups in all compounds. The Cu-S distances are found in the range 2.268(5)-2.417(8) Å, being close to thetypical CuI-S coordination bond distances. Strong d-
interactions between d-electrons of the copper ions and-electrons of the ET molecules can be expected through the Cu-S coordination bonds. ET molecules behave astrans-bidentate ligands bonding to two different copper ions in 1 and 3, as cis-bidentate ligands in 2, 5, and 6, andas monodentate ligands in 4. In the crystal structure of 3, there are two types of ET molecules in the crystalstructure, where the first type is a trans-bidentate ligand and the second forms a stacking structure by itself.Compounds 1, 2, 4, and 6 show semiconducting behavior down to low temperature (
RT = 1.6 × 10-2 S cm-1 andEa = 122 meV for 1, RT = 2.1 S cm-1 and Ea = 21 meV for 2, RT = 5.4 × 10-4 S cm-1 and Ea = 239 meVfor 4, and RT = 5.1 × 10-2 S cm-1 and Ea = 207 meV for 6). On the other hand, in 3, a metal-like region isobserved along the b-axis and c-axis, due to the contribution of stacked ET molecules, and a metal-semiconductortransition occurs at 280 and 270 K, respectively. Also, 5 exhibits metallic conductivity in the temperature ranges240-300 and 200-300 K along the b-axis and c-axis, respectively, despite the oxidation state of ET with 2+.
interactions between d-electrons of the copper ions and-electrons of the ET molecules can be expected through the Cu-S coordination bonds. ET molecules behave astrans-bidentate ligands bonding to two different copper ions in 1 and 3, as cis-bidentate ligands in 2, 5, and 6, andas monodentate ligands in 4. In the crystal structure of 3, there are two types of ET molecules in the crystalstructure, where the first type is a trans-bidentate ligand and the second forms a stacking structure by itself.Compounds 1, 2, 4, and 6 show semiconducting behavior down to low temperature (RT = 1.6 × 10-2 S cm-1 andEa = 122 meV for 1, RT = 2.1 S cm-1 and Ea = 21 meV for 2, RT = 5.4 × 10-4 S cm-1 and Ea = 239 meVfor 4, and RT = 5.1 × 10-2 S cm-1 and Ea = 207 meV for 6). On the other hand, in 3, a metal-like region isobserved along the b-axis and c-axis, due to the contribution of stacked ET molecules, and a metal-semiconductortransition occurs at 280 and 270 K, respectively. Also, 5 exhibits metallic conductivity in the temperature ranges240-300 and 200-300 K along the b-axis and c-axis, respectively, despite the oxidation state of ET with 2+.