In-Situ Measurements and Molecular Orientation by External Reflection Spectrometry of Liquid-Liquid Interfacial Adsorbates of Porphyrins.
| Project/Area Number |
13650865
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
工業分析化学
|
|---|
| Research Institution | Akita University |
|---|
Principal Investigator |
MORIYA Yoshio Akita University, Faculty of Engineering and Resourse Science, Research Assistant, 工学資源学部, 助手 (30241673)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OGAWA Nobuaki Akita University, Faculty of Engineering and Resourse Science, Professor, 工学資源学部, 教授 (80169193)
|
|---|
| Project Period (FY) |
2001 – 2003
|
| Project Status |
Completed (Fiscal Year 2003)
|
| Budget Amount *help |
¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2003: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 2002: ¥500,000 (Direct Cost: ¥500,000)
|
|---|
| Keywords | liquid-liquid interface / protonated porphyrins / interfacial adsorbate / external reflection / partial internal reflection / molecular orientation / interface selection rule / aggregate / 吸着状態 / 界面配向 / p-偏光スペクトル / 界面濃度 / 部分反射 / J-会合体 |
|---|
| Research Abstract |
The authors investigated the interfacial adsorption states of lipophilic-porphyrins (H_2P) in a protonated form (H_4PX_2) at the inert organic solvent/aqueous inorganic acid (HX) solution interface by development of in situ measurement devices for partial reflection spectrometry, including external reflection (ER) and partial internal reflection (PIR).
1.Stoichiometric analysis of protonated tetraphenylporphyrin in an aggregate (H_4PX_2)_<n,i> was accomplished using a simple device comprising a liquid cell and prisms. (1)In the toluene-4 M H_2SO_4 system, ER spectrometry was effective to distinguish interfacial adsorbates from lipophilic solute in the organic phase (H_2P)_o. (2)In the dodecane-4 M H_2SO_4 system, all (H_2P)_o was protonated to yield (H_4PX_2)_<n,i> and aqueous species, H_4P^<2+>_<aq>. The relationship of reflection absorbance at each of bands for interfacial molecular density [H_4PX_2]_i suggested that the interfacial adsorption state changed from a monolayer form to a
… More
multilayer one with a different reflection coefficient. (3)The saturated interfacial molecular density in the dodecane-4 M H_2SO_4 system was estimated to be 1.20×10^<-10> mol cm^<-2> ; it yields a tilt angle 47°of pyrrole ring plane against the interface normal.
2.No aggregation was found in the lipophilic tetraphenylporphyrin derivatives with substituent at ortho-position in meso-phenyl group. Whereas, protonated tetra-p-torylporphyrin could associate to form some aggregate. These suggest the molecular association is depend on the rotation nature of phenyl-group to yield a planar-type molecular structure.
3.The incident angle dependence of reflection spectra was studied using a home-made variable-angle device. Positive and negative bands have been observed in the p-polarized PIR spectra, whose band location correspond to those in p-polarized ER spectra. Nevertheless, the bands in the p-PIR exhibited reversed sign to those of p-ER spectra. These suggest that the interface selection rule of the p-PIR spectrometry has a reversal rule of p-ER, and PIR can also be used for the analysis of molecular orientation. Less
|
Report
(4 results)
Research Products
(15 results)
