2004 Fiscal Year Final Research Report Summary
Structural Study of Photo-Induced Phenomena in Crystals by Synchrotron Radiation Crystallography
| Project/Area Number |
14340187
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | University of Hyogo (2004)
Himeji Institute of Technology (2002-2003) |
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Principal Investigator |
TORIUMI Koshiro University of Hyogo, Graduate School of Material Science, Professor, 大学院・物質理学研究科, 教授 (90124221)
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| Co-Investigator(Kenkyū-buntansha) |
OZAWA Yoshiki University of Hyogo, Graduate School of Material Science, Associate Professor, 大学院・物質理学研究科, 助教授 (40204200)
MITSUMI Minoru University of Hyogo, Graduate School of Material Science, Research Associate, 大学院・物質理学研究科, 助手 (20295752)
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| Project Period (FY) |
2002 – 2004
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| Keywords | photo-excited state / X-ray crystal structural analysis / synchrotron radiation / photo-induced phenomenon / transition metal complex / low-temperature vacuum X-ray camera / micro-crystal structure analysis / low-temperature structure analysis |
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| Research Abstract |
In order to reveal the photo-induced small structural changes using the single crystal structure analyses, it has been understood that the rise in heat of the crystal specimen according to the light irradiation should be a significant problem. We succeeded in the suppression of the crystal heating less than 0.1K by introducing the new timesharing IP multiple exposure method, in which incident X-ray and excitation light was intermitted synchronously by using a couple of rotary choppers.
Photo-excited structure analysis was applied to the luminescent dicopper(I) complexes [Cu_2I_2(PPh_3)_2(4,4'-bpy)]_∞, which consist of {Cu_2I_2 } planer units bridged by diimine ligands constructing infinite chain structures. Single crystal X-ray diffraction experiments under photo-illumination were performed at 40 K by using the low-temperature vacuum X-ray camera at SPring-8 BL02B1 beamline. Two set of reflection data of intensity changes owing to light irradiation were measured by the timesharing IP mu
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ltiple exposure method under two laser light of wavelengths on the absorption band (442 nm) and on its tail (532 nm). Photo-difference Fourier syntheses for the 442 nm irradiation data show significant positive and negative peaks around Cu and I atoms, though that for the 532 nm data show no significant peak. The least-squares refinement based on the photo-induced intensity changes revealed that ca. 1.1% of the Cu and I atoms moved and resulted in the shortening of the Cu-I bond and I...I distance of 0.2Å and 0.6Å, respectively.
Crystal structure analysis of the photo-induced nitrene has been determined successfully by using the host-guest complex of [(PhCH_2)_2NH_2]^+[m-C_6H_4(N_3)(COO)]^-. The intensity data were collected at 25 K using the low-temperature vacuum X-ray camera at SPring-8 before and after UV-irradiation with a high-pressure mercury lamp. It has been revealed that ca. 7% of the triplet nitrene and the isolated nitrogen molecule were generated and the C-N bond distance in the triplet nitrene was 1.34(4)Å. Less
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