Insulator-Metal Transition by Photochemical Doping Using Electron-Transfer Bond Fragmentation
Project/Area Number |
11650871
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
有機工業化学
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Research Institution | Nagoya University |
Principal Investigator |
ISHIGURO Katsuya Nagoya University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (40202981)
|
Project Period (FY) |
1999 – 2000
|
Project Status |
Completed (Fiscal Year 2000)
|
Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1999: ¥2,600,000 (Direct Cost: ¥2,600,000)
|
Keywords | Photoinduced Electron-Transfer / Photochemical Doping / Insulator-Metal Transition / Solid State Photochemistry / TCNQ / Bond Fragmentation |
Research Abstract |
Tetracyanoqunodimethane (TCNQ) has high electron affinity and partially doped π-stacking TCNQ molecular column acts as an organic metal. Typically, TCNQ forms charge-transfer (CT) complexes with electron donors likes as tetrathiafulvalene which show high electrical conductivity. Conductivity should be appeared if proper amount of electrons are doped by photoinduced electron transfer (PET) reactions with sacrificial donors. In order to explore the photochemical electron doping of TCNQ, the PET reaction between TCNQ and some donors in solid phase was investigated. The irradiation with UV light of mixed powder of tetracyanoqunodimethane (TCNQ) and dimeric donor (D-D) resulted in the formation of TCNQ indicating that TCNQ could be doped by irreversible photoinduced electron transfer and C-C cleavage of D-D^+. The donors (D-D) would be decomposed after one-electron oxidation into cations (D^+) and radicals (D^-) quickly by C-C bond cleavase. In addition, the radicals (D^-) with extremely low oxidation potential could act as another dopant to TCNQ.The spectroscopic results, however, indicated that electrons doped to TCNQ might not be delocalized over the TCNQ molecular column but localized in the TCNQ^--D^+ salt ; i.e., the conducting column in the TCNQ crystal was broken upon doping with sacrificial electron donors. Photo-generation of electrical conductor with this method might be achieved by use of self-assemble or amorphous electron transfer materials.
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Report
(3 results)
Research Products
(15 results)