Synthesis of crownophanes possessing three pyridine rings
摘要:
Novel crownophanes with three pyridine moieties (pyridinocrownophanes 4 and 5) were prepared by means of intramolecular [2+2] photocycloaddition of vinylpyridine derivatives. In the liquid-liquid extraction of heavy metal cations, 4 and 5 exhibited high efficiency toward Ag+. Comparing the high extractability and complexing stability constant for Ag+ to those of the corresponding pyridinocrownophanes 2 and 3 and observing the H-1 NMR spectra in the presence of Ag+. the ethereal oxygen atoms and the three nitrogen atoms were found efficiently and cooperatively to act as ligating sites. (c) 2007 Elsevier Ltd. All rights reserved.
Synthesis of crownophanes possessing three pyridine rings
摘要:
Novel crownophanes with three pyridine moieties (pyridinocrownophanes 4 and 5) were prepared by means of intramolecular [2+2] photocycloaddition of vinylpyridine derivatives. In the liquid-liquid extraction of heavy metal cations, 4 and 5 exhibited high efficiency toward Ag+. Comparing the high extractability and complexing stability constant for Ag+ to those of the corresponding pyridinocrownophanes 2 and 3 and observing the H-1 NMR spectra in the presence of Ag+. the ethereal oxygen atoms and the three nitrogen atoms were found efficiently and cooperatively to act as ligating sites. (c) 2007 Elsevier Ltd. All rights reserved.
Novel crownophanes with three pyridine moieties (pyridinocrownophanes 4 and 5) were prepared by means of intramolecular [2+2] photocycloaddition of vinylpyridine derivatives. In the liquid-liquid extraction of heavy metal cations, 4 and 5 exhibited high efficiency toward Ag+. Comparing the high extractability and complexing stability constant for Ag+ to those of the corresponding pyridinocrownophanes 2 and 3 and observing the H-1 NMR spectra in the presence of Ag+. the ethereal oxygen atoms and the three nitrogen atoms were found efficiently and cooperatively to act as ligating sites. (c) 2007 Elsevier Ltd. All rights reserved.