Hydrogen-bonding tetrathiafulvalene (TTF) conductors: Carrier generation by self-doping
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- 作者：Y. Kobayashi ; M. Yoshioka ; K. Saigo ; D. Hashizume ; T. Ogura
- 关键词：Salt-bridge hydrogen bond ; Protonation of TTF ; Protic doping ; AC conductivity ; Isotope effect
- 刊名：Physica B
- 出版年：2010
- 出版时间：1 June 2010
- 年：2010
- 卷：405
- 期：11, Supplement 1
- 页码：S23-S26
- 全文大小：401 K
文摘
A salt-bridge-type hydrogen bonding salt, ammonium tetrathiafulvalene-2-carboxylate () has a conductivity of 2.2×10–4 S/cm at 300 K. is neither a charge transfer complex nor an ion-radical salt, suggesting that it is a new type of molecular conductor. The carrier generation mechanism in was investigated using spectroscopic analysis. The crystal structure of was determined using powder X-ray crystallography. The TTF moiety is stacked in one dimension with a helical columnar hydrogen-bonded network and S…S contacts, forming a two-dimensional intermolecular interaction in a supramolecular TTF array. Molecular orbital calculations showed that the SOMO of the embedded radical is in a quasi-closed shell configuration (an f-electron-like configuration), suggesting a stabilization of the unpaired electron in the molecular array in the solid. The AC conductivity of and the deuterium-substituted compound shows a large isotope effect below 200 K, implying a correlation between the salt-bridge hydrogen bonding moiety and the transport phenomena.