2001 Fiscal Year Annual Research Report

内殻励起分子の核の運動と解離ダイナミクス

Research Project

Project/Area Number	11440120
Research Institution	Tohoku University
Principal Investigator	上田潔東北大学, 多元物質科学研究所, 助教授 (50151791)
Co-Investigator(Kenkyū-buntansha)
Keywords	内殻励起分子 / 共鳴オージェ電子分光 / 多重イオン同時計測 / 運動量画像測定 / 対称性低下 / 振電相互作用 / 振動分光
Research Abstract	高輝度放射光実験施設SPring-8で供給される非常に狭いバンドパスの単色軟X線を用いて内殻励起状態の核の運動と解離ダイナミクスを調べることを目的として以下の研究を行なった。 (1)水分子H_2OのO1s電子を2b_2軌道に励起した内殻励起状態のポテンシャル曲面には浅い井戸が存在し、内殻励起に伴い変角振動と伸縮振動が励起されるが、この内殻励起状態からの共鳴オージェ電子放出を高分解能測定し、内殻励起状態の振動を選別することにより、オージェ終状態の核の運動を制御できることを見出した。 (2)二酸化炭素分子CO_2のC又はOの1s電子を最低非占有分子軌道2π_uに励起すると変角振動を介したレナー・テラー分裂が起こるが、曲がったC_<2v>構造におけるA_1励起状態が曲がった安定構造をとりB_1励起状態が直線となることを三重イオン同時計測運動量画像測定により明らかにし、A_1・B_1内殻励起状態を分離した振動分光に成功した。 (3)三フッ化ホウ素分子BF_3のB1s電子を最低非占有分子軌道2a_2"に励起すると正三角錐安定構造を目指して中央のB原子が面外に移動し始めるが、この核の運動を角度分解イオン収量法、高分解能共鳴オージェ分光法、四重イオン同時計測運動量画像測定法を用いてストロボ撮影した。 (4)四フッ化メタン分子CF_4や四フッ化シラン分子SiF_4のF1s電子をほとんど縮退した最低非占有分子軌道t_2/a_1に励起すると、ヤン・テラー効果、擬ヤン・テラー効果によって、T_d対称な構造からC_<3v>対称な構造に対称性を低下させる核の運動が誘起され、非等方的な解離を引き起こす。角度分解共鳴オージェ電子スペクトルに現れるF+イオンのドップラーシフトによりこの核の運動を捉えることに成功した。

Research Products
(11 results)

All Other

All Publications (11 results)

[Publications] Yuichiro Shimizu: "Sub-natural-width angle-resolved resonant Auger electron spectroscopy of atoms and molecules on the high-resolution soft X-ray monochromator at SPring-8"J.Electron Spectroscopy and Related Phenomena. 114-116. 63-70 (2001)
[Publications] Masashi Kitajima: "Angular distribution measurements for spin-orbit-state-resolved S 2p photoelectrons of SF_6 in the shape-resonance region"Physical. Review A. 63. 050703(R) (2001)
[Publications] Atsunari Hiraya: "H_2^+ formation from H_2O^+ mediated by the core-excitation-induced nuclear motion in H_2O"Physical. Review A. 63. 042705 (2001)
[Publications] Kiyoshi Ueda: "Angle-resolved electron and ion spectroscopy apparatus on the soft X-ray photochemistry beamline BL27SU at SPring-8"Nuclear Instrum. Methods A. 467-468. 1502-1504 (2001)
[Publications] Haruhiko Ohashi: "Mochochromator for a soft X-ray photochemistry beamline BL27SU at SPring-8"Nuclear Instrum. Methods A. 467-468. 533-537 (2001)
[Publications] Alberto De Fanis: "Control of nuclear motion in the B 1b_2 ionic state of water via Auger resonant Raman process"J. Physics B : Atomic, Molecular and Optical Physics. 35. L23-L29 (2002)
[Publications] Hiroaki Yoshida: "Symmetry-resolved vibrational spectroscopy for the C 1s^<-1>2π_u Renner-Teller pair states in CO_2"Physical Review Letters. 88. 083001 (2002)
[Publications] Yoko Muramatsu: "Direct probe of the bent and linear geometries of the core-excited Renner-Teller pair states by means of the triple-ion-coincidence momentum imaging technique"Physical Review Letters. 88(in press). (2002)
[Publications] K.iyoshi Ueda: "Nuclear motion, symmetry breaking and dissociation dynamics of coreexcited polyatomic molecules"Surface Review and Letters. (in press). (2002)
[Publications] Yoko Muramatsu: "Bent and linear geometries of Renner-Teller pair states in CO_2 probed by triple-ion-coincidence momentum imaging"Surface Review and Letters. (in press). (2002)
[Publications] Kazumasa Okada: "Symmetry breaking of SiF_4 molecule by F 1s excitation"Surface Review and Letters. (in Press).

2001 Fiscal Year Annual Research Report

内殻励起分子の核の運動と解離ダイナミクス

Principal Investigator

上田 潔 東北大学, 多元物質科学研究所, 助教授 (50151791)

Research Products

[Publications] Yuichiro Shimizu: "Sub-natural-width angle-resolved resonant Auger electron spectroscopy of atoms and molecules on the high-resolution soft X-ray monochromator at SPring-8"J.Electron Spectroscopy and Related Phenomena. 114-116. 63-70 (2001)

[Publications] Masashi Kitajima: "Angular distribution measurements for spin-orbit-state-resolved S 2p photoelectrons of SF_6 in the shape-resonance region"Physical. Review A. 63. 050703(R) (2001)

[Publications] Atsunari Hiraya: "H_2^+ formation from H_2O^+ mediated by the core-excitation-induced nuclear motion in H_2O"Physical. Review A. 63. 042705 (2001)

[Publications] Kiyoshi Ueda: "Angle-resolved electron and ion spectroscopy apparatus on the soft X-ray photochemistry beamline BL27SU at SPring-8"Nuclear Instrum. Methods A. 467-468. 1502-1504 (2001)

[Publications] Haruhiko Ohashi: "Mochochromator for a soft X-ray photochemistry beamline BL27SU at SPring-8"Nuclear Instrum. Methods A. 467-468. 533-537 (2001)

[Publications] Alberto De Fanis: "Control of nuclear motion in the B 1b_2 ionic state of water via Auger resonant Raman process"J. Physics B : Atomic, Molecular and Optical Physics. 35. L23-L29 (2002)

[Publications] Hiroaki Yoshida: "Symmetry-resolved vibrational spectroscopy for the C 1s^<-1>2π_u Renner-Teller pair states in CO_2"Physical Review Letters. 88. 083001 (2002)

[Publications] Yoko Muramatsu: "Direct probe of the bent and linear geometries of the core-excited Renner-Teller pair states by means of the triple-ion-coincidence momentum imaging technique"Physical Review Letters. 88(in press). (2002)

[Publications] K.iyoshi Ueda: "Nuclear motion, symmetry breaking and dissociation dynamics of coreexcited polyatomic molecules"Surface Review and Letters. (in press). (2002)

[Publications] Yoko Muramatsu: "Bent and linear geometries of Renner-Teller pair states in CO_2 probed by triple-ion-coincidence momentum imaging"Surface Review and Letters. (in press). (2002)

[Publications] Kazumasa Okada: "Symmetry breaking of SiF_4 molecule by F 1s excitation"Surface Review and Letters. (in Press).

上田潔東北大学, 多元物質科学研究所, 助教授 (50151791)