Two new spectroscopic methods to detect the optical activity of liquid-liquid interfaces have been developed. The first one is the centrifugal liquid membrane （CLM） method combined with a conventional circular dichr...Two new spectroscopic methods to detect the optical activity of liquid-liquid interfaces have been developed. The first one is the centrifugal liquid membrane （CLM） method combined with a conventional circular dichroism （CD） spectropolarimetry and the second one is a more interfacial specific second harmonic generation CD （SHG-CD） spectrometry. In the CLM-CD method, a cylindrical glass cell containing small amounts of organic and aqueous phases was rotated at about 7000 r/min in a sample chamber of a CD spectropolarimeter to generate an interface with a high specific interfacial area between the two-phase liquid membranes. The CD spectra of the J-aggregate of protonated 5,10,15, 20-tetraphenylporphyrin formed at the toluene-sulfuric acid interface have been measured, As for the SHG-CD, a circularly polarized wavelength-variable fs-laser system was constructed to measure the interfacial SHG spectra of a flat liquid-liquid interface. The ion-associated aggregation of a water-soluble anionic porphyrin promoted with a cationic amphiphile at the heptane-water interface was observed by this technique and the observed SHG-CD spectra proved the generation of a characteristic oPtical activity accompanied by the formation of the interfacial aggregate of inherently achiral porphyrin molecules. These methods will pioneer a new field of interfacial chiral chemistry in the studies of solvent extraction mechanisms.展开更多
Poly{bis[4-（4＇-（S）-2-methylbutoxy）biphenyloxy]phosphazene}（PP-C） was designed and successfully synthesized, and then characterized by means of FT-IR spectroscopy, ~1H- and ^（31）P-NMR, GPC spectroscopy, wide a...Poly{bis[4-（4＇-（S）-2-methylbutoxy）biphenyloxy]phosphazene}（PP-C） was designed and successfully synthesized, and then characterized by means of FT-IR spectroscopy, ~1H- and ^（31）P-NMR, GPC spectroscopy, wide angle X-ray diffraction and differential scanning calorimetry. The results indicated that for PP-C, the M_w is 2.18×10~5 and the PDI is 1.96. PP-C was a kind of crystallized polymer with a crystallizing point of -2.0 ℃ and a melting point of 28 ℃. The conformational chirality of the PP-C molecules was studied using circular dichroism spectrum. It was found that in dilute THF solution, the biphenyl groups in the PP-C molecules twisted randomly. However, when the PP-C formed aggregates, the biphenyl groups tended to twist single-handedly, which was controlled by the adjacent chiral alkoxy groups.展开更多
基金Supported by the Grant-in-Aid for Scientific Research (No. 16105002) from the Ministry of Education, Science, Sports, and Culture, Japan
文摘Two new spectroscopic methods to detect the optical activity of liquid-liquid interfaces have been developed. The first one is the centrifugal liquid membrane （CLM） method combined with a conventional circular dichroism （CD） spectropolarimetry and the second one is a more interfacial specific second harmonic generation CD （SHG-CD） spectrometry. In the CLM-CD method, a cylindrical glass cell containing small amounts of organic and aqueous phases was rotated at about 7000 r/min in a sample chamber of a CD spectropolarimeter to generate an interface with a high specific interfacial area between the two-phase liquid membranes. The CD spectra of the J-aggregate of protonated 5,10,15, 20-tetraphenylporphyrin formed at the toluene-sulfuric acid interface have been measured, As for the SHG-CD, a circularly polarized wavelength-variable fs-laser system was constructed to measure the interfacial SHG spectra of a flat liquid-liquid interface. The ion-associated aggregation of a water-soluble anionic porphyrin promoted with a cationic amphiphile at the heptane-water interface was observed by this technique and the observed SHG-CD spectra proved the generation of a characteristic oPtical activity accompanied by the formation of the interfacial aggregate of inherently achiral porphyrin molecules. These methods will pioneer a new field of interfacial chiral chemistry in the studies of solvent extraction mechanisms.
基金Funded by the National Natural Science Foundation of China(No.21274098)
文摘Poly{bis[4-（4＇-（S）-2-methylbutoxy）biphenyloxy]phosphazene}（PP-C） was designed and successfully synthesized, and then characterized by means of FT-IR spectroscopy, ~1H- and ^（31）P-NMR, GPC spectroscopy, wide angle X-ray diffraction and differential scanning calorimetry. The results indicated that for PP-C, the M_w is 2.18×10~5 and the PDI is 1.96. PP-C was a kind of crystallized polymer with a crystallizing point of -2.0 ℃ and a melting point of 28 ℃. The conformational chirality of the PP-C molecules was studied using circular dichroism spectrum. It was found that in dilute THF solution, the biphenyl groups in the PP-C molecules twisted randomly. However, when the PP-C formed aggregates, the biphenyl groups tended to twist single-handedly, which was controlled by the adjacent chiral alkoxy groups.
