量研学術機関リポジトリ「QST-Repository」は、国立研究開発法人 量子科学技術研究開発機構に所属する職員等が生み出した学術成果（学会誌発表論文、学会発表、研究開発報告書、特許等）を集積しインターネット上で広く公開するサービスです。 Welcome to QST-Repository where we accumulates and discloses the academic research results(Journal Publications, Conference presentation, Research and Development Report, Patent, etc.) of the members of National Institutes for Quantum Science and Technology.
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Structure Analysis and Derivation of Deformed Electron Density Distribution of Polydiacetylene Giant Single Crystal by the Combination of X-ray and Neutron Diffraction Data
利用統計を見る
The crystal structure of polydiacetylene giant single crystal has been
analyzed on the basis of the two different methods of wide-angle neutron diffraction and X-ray diffraction. The X-ray result gives us the total electron density distribution [ρ(x)] of polymer chain. The neutron result tells the positions of atomic nuclei, which can allow us to speculate the electron density distributions [ρ0(x)] around the nonbonded isolated atoms. As a result, the so-called bonded (or deformed) electron density Δρ(x) [≡ ρ(x) − ρ0(x) = ρX(x) − ρN(x)], i.e., the electron density distribution due to the conjugation among the covalently bonded atoms along the polymer chain, can be estimated using the two information obtained by the X-ray and neutron data analyses (the so-called X-ray−neutron subtraction (X−N) method). The present report is the first example of the application of X−N method to the synthetic polymer species. The Δρ(x) derived for polydiacetylene was found similar to that of the low-molecular-weight model compound having the similar electronically conjugated chemical formula. The Δρ(x) was calculated by the density functional theory, which was in a good agreement with the experimental result qualitatively.
Structure Analysis and Derivation of Deformed Electron Density Distribution of Polydiacetylene Giant Single Crystal by the Combination of X-ray and Neutron Diffraction Data
