The first phenalenyl-based neutral radical molecular conductor
The first phenalenyl-based neutral radical molecular conductor
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DOI：
10.1021/ja992040c
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发表时间：
1999-11-10
影响因子：
15
通讯作者：
Haddon, RC
中科院分区：
文献类型：
--
作者：
Chi, X;Itkis, ME;Haddon, RC
我们报道了螺联苯基自由基的制备、结晶和固态表征。晶体结构表明，自由基在固态下是单体，并且没有属于范德华原子分离范围内的分子间接触。磁化率测量显示在 10-400 K 温度范围内的居里行为（每个分子 1 个自旋），证实了固体中存在非相互作用自旋。该化合物的室温电导率 sigma = 0.05 S/cm，是中性自由基导体迄今为止最高的电导率。我们认为自由基的基态对应于简并的莫特-哈伯德绝缘体。我们假设存在离域能带，这些能带负责传输特性，但通过与现场库仑相关能相对应的能隙与绝缘基态分开。鉴于晶格中存在孤立分子，电导率的大小、能带传输的发现以及导带的宽度（0.5 eV）都是前所未有的。
We report the preparation, crystallization, and solid-state characterization of a spiro-biphenalenyl radical. The crystal structure shows that the radical is monomeric in the solid state and without intermolecular contacts that fall within the van der waals atomic separation. Magnetic susceptibility measurements show Curie behavior (1 spin per molecule) throughout the temperature range 10-400 K, confirming the presence of noninteracting spins in the solid. The compound shows a room-temperature conductivity of sigma = 0.05 S/cm, the highest yet for a neutral radical conductor. We suggest that the ground state of the radical corresponds to a degenerate Mott-Hubbard insulator. We postulate the presence of delocalized energy bands that are responsible for the transport properties but that are separated from the insulating ground state by an energy gap corresponding to the on-site Coulombic correlation energy. Given the presence of isolated molecules in the crystal lattice, the magnitude of the conductivity, the finding of band transport, and the width of the conduction band (0.5 eV) are unprecedented.