| Budget Amount *help |
¥2,990,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥390,000)
Fiscal Year 2007: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2006: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
Structures and physical properties of subnanometer metal particles are very interesting. We studied a preparation and fundamental properties of silver nanoclusters stabilized by dithiocarbamate ligators. Additionally, we studied for size-selective preparations of gold nanoparticles.
The silver nanocrystals are prepared by reacting silver nitrate with hydrophilic dithiocarbamate in water. The X-ray crystal structure determination reveals that the nanocrystal was composed of Ag_6 and Ag_8S clusters linked by two Ag cations. In the Ag_8S cluster, where all Ag atoms reside within bonding distances to S, six Ag form a chair-shaped six-membered ring, at the center of which S atom resides and the rest Ag atoms are above and below the suffer atom. The Ag_6 cluster has two parallel triangles with different edge length. The Ag_8S cluster and Ag_6 cluster forms regular two-dimensional seat structure through Ag-Ag bond, and all silver atoms have relatively short Ag^<+->Ag^+bonding.
We also studied size-selective preparations of gold nano particles. The size of them can be controlled through a combined use of either of four methods; control of speed of addition of reducing agent, pH control of reaction medium, etching by oxitant, and thermal growing of resulted nanoparticles. These methods gave mono-dispersed gold nano particles with narrow distributions in selected core diameters with 1.3nm, 1.7nm, 2.0nm, 2.8nm, 4.5nm, and 8.6nm.
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