1994 Fiscal Year Final Research Report Summary
VUV Photo-reactions over Solid Surfaces studied by Techniques of Surface Science
| Project/Area Number |
05650034
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
表面界面物性
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| Research Institution | Hokkaido University |
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Principal Investigator |
SATO Shinri Catalysis Research Center, Hokkaido University, Associate Professor, 触媒化学研究センター, 助教授 (70001724)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Surface photochemistry / Iron pentacarbonyl / photodecomposition / Surface spectroscopy / Reaction intermediate |
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| Research Abstract |
Surface photochemistry has been applied to the preraration of thin films of metal and semiconductor for microelectronics. The purpose of this study is to investigate a mechanism of the photodecomposition of iron pentacarbonyl(Fe(CO)_5, IPC)adsorbed on solid surfaces at low temperatures using IR reflection absorption spectroscopy, X-ray photoelectron spectroscopy, and thermal desorption spectroscopy, and to examine effects of the physical and chemical properties of solid surface on the reactions.The results are summarized as follows.
1.IPC is molecularly adsorbed on clean Ag, Au(111), and SiO_2 surfaces at tenperatures bellow 150K and undergoes photodecarbonylation upon irradiation with the light of wavelengths < 360nm.The photoproduct is the oligomer of Fe(CO)_4, which is quite stable under illumination but undergoes thermal decomposition at temperatures above 300K to deposit Fe metal on the surface. A mechanism of the thermal process depends on the catalytic properties of substrate surface.
2.The dependence of photo-decarbonylation yield on the wavelength of light was observed for Ag and Au substrates and found different from the absorption spectrum of gas phase IPC.On Ag surfaces the yield is maximized at around 320 nm, at which gaseous IPC shows little absorption, while on Au(111) the decarbonylation occurs at significant yield at around 320nm but exhibits no maximum yield in longer wavelength range. These results show that the adsorption of IPC on solid surfaces would lead to the red shift of absorption spectrum. In addition, the photoexcitation of Ag surface plasmon(3.88eV * 320nm)could cause the decarbonylation of adsorbed IPC.
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