1989 Fiscal Year Final Research Report Summary
Studies on the separation and detection unstable reaction intermediate by means of low temperature HPLC.
| Project/Area Number |
63470034
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
分析・地球化学
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| Research Institution | Kobe Women's College of Pharmacy |
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Principal Investigator |
MORIYASU Masataka Kobe Women's College of Pharmacy, associate professor, 薬学部, 助教授 (40102107)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Low temperature HPLC / rotamer / tautomer / ternary complex / beta-diketone / cyclohexanone / formanilide / dithiocarbamate chelate |
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| Research Abstract |
1. Rotamers of amids were separated by means of low-temperature HFLC(LT-HPLC), and their absorption spectra were measured by photodiode-array detector. Remarkable difference was found for UV-spectra of Z- and E-rotamer of formanilide. This was explained in terms of larger steric repulsion between benzene ring and oxygen atom in Z-form than that between benzene ring and hydrogen atom in E-form.
2. Keto- and enol-tautomers of several ketones were separated by means of LT-HPLC, and their absorption spectra were measured. Their spectra can reasonably be explained by comparing the known, compounds structurally resemble. The formation of labile hemiacetal was also found for fluoro-substituted beta-diketones. Their UV spectra quite resembled unconjugated keto-tautomer.
The reaction between BF_3 and beta-diketones or metal beta-diketone chelates was traced continuously. In the course of the reaction between Fe(AA)_3 and BF_3 the presence of unstable violet intermediate was observed. We tried the
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detection of the violet intermediate by LT-HPLC, but could not detect it even when HPLC was carried out below -70 ﾟC.
LT-HPLC of cyclohexanone at -60ﾟC gave the separation of small peak, which was reasonably be attributable to the enoltautomer of cyclohexanone having vinyl alcohol structure.
3. Ternary complex formation between dithiocarbamates(DTC) and several other ligands of various metals was investigated by means of LT-HPLC. DTC chelates such as Zn(II), Tl(I), Fe(III), and Mn(III) whose stability constants are rather small, hardly gave peaks on the chromatograms when operated at room temperature.
However, by LT-HPLC these chelates were eluted quantitatively because dissociation of the chelate was retarded at low temperatures. The ternary complex formation of DTC, xanthates, dithizone, and other ligands was observed for several metal ions. It is interesting to note that the UV-visible spectra of the formed ternary complex differed markedly from original binary complexes when the formed ternary complex is very stable. Less
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