Kaneko Satoshi, Hashikawa Yoshifumi, Fujii Shintaro, Murata Yasujiro, Kiguchi Manabu
Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan.
Institute for Chemical Research, Kyoto University, Gokasho, Uji-city, Kyoto, 611-0011, Japan.
Chemphyschem. 2017 May 19;18(10):1229-1233. doi: 10.1002/cphc.201700173. Epub 2017 Mar 21.
A water molecule exhibits characteristic properties on the basis of hydrogen bonding. In the past decade, single water molecules placed in non-hydrogen-bonding environments have attracted growing attention. To reveal the fundamental properties of a single water molecule, endohedral fullerene H O@C is an ideal and suitable model. We examined the electronic properties of H O@C by performing single-molecule measurements. The conductance of a single molecular junction based on H O@C was found to be comparable to that of empty C . The observed values were remarkably higher than those obtained for conventional molecular junctions due to the effective hybridization of the π-conjugated system to the metal electrode. Additionally, the results undoubtedly exclude the possibility of electrostatic contact of entrapped H O with the carbon wall of C . We finally concluded that H O entrapped inside a C cage can be regarded as an electrostatically isolated molecule.
水分子基于氢键展现出其特征性质。在过去十年中，置于非氢键环境中的单个水分子越来越受到关注。为了揭示单个水分子的基本性质，内嵌富勒烯H₂O@C₆₀是一个理想且合适的模型。我们通过进行单分子测量来研究H₂O@C₆₀的电子性质。发现基于H₂O@C₆₀的单分子结的电导与空的C₆₀相当。由于π共轭体系与金属电极的有效杂化，观测值显著高于传统分子结所获得的值。此外，结果无疑排除了被困的H₂O与C₆₀碳壁发生静电接触的可能性。我们最终得出结论，被困在C₆₀笼内的H₂O可被视为一个静电隔离的分子。
