Optically active linear polyimides and hyperbranched poly (amic acid-imide) were prepared by using procedures varying in particular in the maximum temperature employed in their synthesis. The two types of linear polyimides were based on 4,4'-(hexafluoroisopropylidene)diphthalic anhydride and 1,2-diaminocylohexane enantiomers or 4,4'-(hexafluoroisopropylidene)diphthalic anhydride and 2,2'-diamino-1,1'-binaphthalene enantiomers. The amine-terminated hyperbranched poly (amic acid-imide) was prepared from 4,4'-(hexafluoroisopropylidene)diphthalic anhydride and 4,4',4″-triaminotriphenylmethane, and its end groups were modified with the chiral selectors N-acetyl-D-phenylalanine or N-acetyl-L-phenylalanine. The final structure of the products was analyzed by IR spectroscopy, and their optical activity was evaluated and confirmed by polarimetry or circular dichroism.
- Klíčová slova
- chiral selector, circular dichroism, optical activity, polarimetry, polyimide,
- MeSH
- anhydridy * chemie MeSH
- cirkulární dichroismus MeSH
- imidy * chemie MeSH
- stereoizomerie MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- anhydridy * MeSH
- imidy * MeSH
Five optically active urea derivatives (1-5) were used as NMR solvating agents for analysis of the optical purity of different 2-arylpropanoic acids commonly used as nonsteroidal anti-inflammatory drugs. These novel chiral solvating agents were more efficient at discriminating the respective enantiomers of targets than the chiral solvating agents known so far, without the need to add a base for achieving the signal splitting. The advantages and limits of the use of these novel chiral solvating agents were studied.
- Klíčová slova
- arylpropanoic acids, binaphthalene, chiral solvating agent, nonsteroidal anti-inflammatory drugs, urea,
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A detailed study of diastereomeric complexes of chiral ureido-1,1'-binaphthalene derivatives with chiral 1-phenylethanol showed that a derivative bearing only one urea unit makes five times more stable complex with (S)-enantiomer than with (R)-enantiomer of the alcohol. This phenomenon could be used in chiral discrimination processes. The influence of individual parts of the structure on the complexation properties is shown. The probable structure of diastereomeric complexes based on experimental results and computational methods is proposed.
- Klíčová slova
- [6]helicene, binaphthalene, calix[4]arene, enantioselective complexation, urea,
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
