| Project/Area Number |
09650984
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
高分子構造・物性(含繊維)
|
|---|
| Research Institution | Tohoku University |
|---|
Principal Investigator |
WATANABE Akira Tohoku University, Institute for Chemical Reaction Science, Associate Professor, 反応化学研究所, 助教授 (40182901)
|
|---|
| Project Period (FY) |
1997 – 1998
|
| Project Status |
Completed (Fiscal Year 1998)
|
| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1997: ¥1,700,000 (Direct Cost: ¥1,700,000)
|
|---|
| Keywords | organosilicon cluster / silicon cluster / organosilicon polymer / quantum size effect / optical and electrical property / emission spectrum |
|---|
| Research Abstract |
The synthesis of organosilicon polymers with various dimensionality and the size of Si skeleton and the optical and electrical properties were studied. The quantum size effects and the effects of the Si-dimensionality were discussed by comparing with those of polysilylene and polysilyne which have one- and two-dimensional Si skeleton, respectively. The silicon nanocluster with a three dimensional Si skeleton was synthesized by the reaction of tetrachlorosilane with Mg metal in THF (tetrahydrofuran).After the formation of the silicon nanocluster dispersed in TI-IF, the alkylchloride was dropwised to the solution to substitute the chloride group by the alkyl group forming a Grignard reagent. The organosilicon nanocluster is soluble to common organic solvents due to the organic substituents surrounding the silicon cluster core. The CPMAS 29Si NMR spectra showed the existence of the Siatom bonding to four Si atoms, which suggests the three dimensional structure of the Si skeleton. The far-JR spectra showed the amorphous silicon structure consisting of Si 4-. 5-, and 6-membered rings. The emission spectrum of the organosilicon nanocluster was observed in the middle wavelength region between organic polysilanes and inorganic silicons. The red shift of the emission spectrum of the organosilicon nanocluster is attributed to the s-conjugation along the three dimensional Si skeleton. Organosilicon clusters with various cluster size were prepared by fractional reprecipitation using THF asa solvent and methanol as a precipitant. The sizes determined by size exclusive chromatography were in the range from 1 to 2 nm. The quantum size effects in the optical properties were exhibited by absorption and emission spectra. The optical band gap was decreased with increasing the cluster size and approached those of inorganic silicons, The organosilicon nanocluster showed the optical properties in the boundary region between organic and inorganic silicons.
|
