| 翻訳と辞書 |
| extended metal atom chains ： ウィキペディア英語版 |
extended metal atom chains
Extended metal atom chains (EMACs) are molecules that consist of a linear string of directly bonded metal atoms, surrounded by organic ligands. These compounds represent the smallest molecular wires. Although such species have no applications, they are researched for the bottom-up approach to nanoelectronics.〔F. Albert Cotton, Carlos A. Murillo and Richard A. Walton (eds.), ''Multiple Bonds Between Metal Atoms'', 3rd edition, Springer (2005).〕
==Structure==
An EMAC molecule contains a linear string of transition metals (typically Cr, Co, Ni, or Cu) that are bonded to each other and are surrounded helically by four long organic ligands. The metal chains are capped at the ends by anions, usually halides. The four organic ligands are made of repeating pyridylamido units, which contain nitrogen donor atoms. Each metal atom is six-coordinate, bonded to two other metals along the axis of the molecule (except terminal metals, which are bonded to one metal and one capping anion) and to four nitrogen atoms perpendicular to the axis.
The organic ligands template the formation of the chains by bringing the metal ions together and aligning them into a linear string. The number of nitrogen atoms in the ligand determines the number of metal atoms that will be incorporated into the chain. Thus, the synthesis yields molecular wires of predetermined length. This feature, in combination with the fact that the molecules have well-defined ends, differentiates EMACs from other kinds of molecular wires: EMACs exist only as distinct molecular entities, they do not aggregate and they do not form periodic structures of repeating units.
Most known EMACs contain from three to nine metal atoms. The longest EMACs that have been constructed so far incorporate nine Ni atoms and have a length of approximately 2 nanometers, although it is estimated that chains with up to 17 metal atoms (4-5 nanometers) could be accessed with currently available ligands.〔S.-M. Peng, C.-C. Wang, Y.-L. Jang, Y.-H. Chen, F.-Y. Li, C.-Y. Mou, M.-K. Leung (2000) “One-dimensional metal string complexes”, J. Magn. Magn. Matter, vol. 209, pp. 80-83. .〕
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「extended metal atom chains」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|