Metallic Conductivity and Ferromagnetic Interaction of Iron(III) d Spins in the Needle Crystals of (Ethylenedithiotetrathiafulvalenoquinone-1,3-dithiolemethide)2·FeBr4 Salt

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• 作者：Takuya Matsumoto ; Tsuyoshi Kominami ; Kazumasa Ueda ; Toyonari Sugimoto ; Toshiji Tada ; Satoru Noguchi ; Harukazu Yoshino ; Keizo Murata ; Motoo Shiro ; Ei-ichi Negishi ; Naoki Toyota ; Satoshi Endo ; and Kazuk
• 刊名：Inorganic Chemistry
• 出版年：2002
• 出版时间：September 9, 2002
• 年：2002
• 卷：41
• 期：18
• 页码：4763 - 4769
• 全文大小：157K
• 年卷期：v.41,no.18(September 9, 2002)
• ISSN：1520-510X

文摘

The 2:1 charge-transfer (CT) salts (1₂·FeBr₄ and 1₂·GaBr₄) of ethylenedithiotetrathiafulvalenoquinone-1,3-dithiolemethide (1) with FeBr₄^- and GaBr₄^- counteranions were obtained as needle crystals, whose structures arealmost the same as each other. The 1 molecules form a one dimensionally stacked column with alternation of theirmolecular axis direction, while the counteranions are aligned in parallel with the 1-stacked columns with the directionof their distorted-tetrahedral geometry maintained. The room-temperature electrical conductivities measured on thesingle crystals of 1₂·FeBr₄ and 1₂·GaBr₄ were 4.6 and 2.1 S cm^-1, respectively. From the temperature dependencesof their electrical conductivities in both cases the electrical conducting properties were metallic between ca. 170and 300 K, but below ca. 170 K converted to be semiconducting and continued till 5 K, although the activationenergies are very small (4-10 meV). For 1₂·FeBr₄ very weak and antiferromagnetic interaction occurred betweenthe d spins of FeBr₄^- ions in the temperature range of ca. 1-300 K. However, below ca. 15 K the ferromagneticinteraction was reversely preferential possibly by participation of the spin of 1.