Polarized total-reflection XAFS spectroscopy at the surface of water solution
問い合わせ番号
SOL-0000001037
ビームライン
BL39XU（X線吸収・発光分光）
学術利用キーワード
| A. 試料 | 原子・分子・ラジカル |
|---|---|
| B. 試料詳細 | 低分子有機材料, 溶液, 膜, イオン, ラジカル, 蛋白質, 医薬品, 環境関連物質 |
| C. 手法 | 吸収、及びその二次過程, 蛍光Ｘ線 |
| D. 手法の詳細 | 反射、屈折, XAFS, EXAFS, XANES |
| E. 付加的測定条件 | 偏光（直線）, 表面, 室温 |
| F. エネルギー領域 | Ｘ線（4～40 keV) |
| G. 目的・欲しい情報 | 化学状態, 結合状態, 分子構造, 局所構造, 電子状態、バンド構造 |
産業利用キーワード
| 階層1 | 環境, 化学製品, 工業材料 |
|---|---|
| 階層2 | 触媒, 環境物質, 日用品（シャンプー,化粧品,歯磨き粉など） |
| 階層3 | 配向膜, タンパク質 |
| 階層4 | 原子間距離, 局所構造, 電子状態, 配向, 価数, 化学状態 |
| 階層5 | XAFS |
分類
A40.40 表面・界面化学, A60.20 環境物質, A80.34 触媒化学, A80.40 環境材料, M40.10 XAFS
利用事例本文
Polarized total-reflection XAFS spectroscopy is a unique technique to study chemical states and local structures of the specified element in molecule on the surface of water solution. Using this technique,we can determine bonding states and coordination structures of the specified atom (ion) at the air-water solution surface. Various compounds including Cr to Rb at the K-edge or Cs to Pb at the L-edge can be investigated at BL39XU of SPring8 because linear polarized X-rays in the horizontal plane orin the vertical plane are available in hard X-ray region of 5-16 keV.
The figure shows X-ray absorption (XANES) spectra at the Zn K-edge measured for the monolayer of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrinato zinc(II) (ZnTPPC) by using horizontally or vertically polarized X-rays. These data reveal the fact that the local structure around Zn in the monolayer is determined:the ZnTPPC molecule allocates a square planar structure formed by four Zn-N bonds in the porphyrin ring, and the plane of the ZnTPPC molecule is oriented parallel to the air-water interface.
Fig. Total-reflection XAFS spectrum using (a) horizontally and (b) vertically polarized X-rays at the Zn K-edge in ZnTPPC.
[ H. Tanida, H. Nagatani and I. Watanabe, The Journal of Chemical Physics 118, 10369-10371 (2003), Fig. 3,
©2003 American Institute of Physics ]
画像ファイルの出典
原著論文/解説記事
誌名
H. Tanida et al., J. Chem. Phys. 118, 10369 (2003).
図番号
Fig. 3
測定手法
Polarized XAFS spectrum is measured by monitoring X-ray absorption of the sample using horizontally or vertically polarized X-rays as a function of the X-ray energy.Synchrotron radiated X-rays are polarized in horizontal plane with the exception of the special case.Liquid samples such as water solution can't be stood vertically although polarized XAFS spectrum for solid samples can be obtained by changing the direction of the sample. Therefore, polarization state of the incident X-ray is needed to change in order to obtain the polarized XAFS spectrum for liquid samples.The polarized XAFS measurement enables us to perform easily at BL39XU of SPring-8 owing toa diamond X-ray phase retarder.
In this solution,XAFS spectra by horizontally and vertically polarized X-rays for the monolayer on the water solution can be obtained without changing the experimental configuration.
Fig. Experimental configuration of polarized total-reflection XAFS measurement.
[ H. Tanida, H. Nagatani and I. Watanabe, The Journal of Chemical Physics 118, 10369-10371 (2003), Fig. 2,
©2003 American Institute of Physics ]
画像ファイルの出典
原著論文/解説記事
誌名
H. Tanida et al., J. Chem. Phys. 118, 10369 (2003).
図番号
Fig. 2
測定準備に必要なおおよその時間
12 時間
測定装置
| 装置名 | 目的 | 性能 |
|---|---|---|
| Total-reflection XAFS measurment system | measurement of total-reflection XAFS spectrum for liquid sample | vertical reflected mirror, liquid level monitor, 19-element pure-Ge SSD |
参考文献
| 文献名 |
|---|
| H. Tanida, H. Nagatani, and I. Watanabe, J. Chem. Phys. 118, 10369 (2003). |
関連する手法
EXAFS/XAFS spectroscopy, X-ray diffraction
アンケート
SPring-8だからできた測定。他の施設では不可能もしくは難しい
ユーザー持ち込み装置を使った
測定の難易度
中程度
データ解析の難易度
中程度
図に示した全てのデータを取るのにかかったシフト数
4～9シフト