Stereochemistry of crown ethers. I. Conformational and dynamic behaviour ofN-tosyl-substituted diaza crown ethers
作者:E. Kleinpeter、M. Gäbler、W. Schroth
DOI:10.1002/mrc.1260260507
日期:1988.5
The variable-temperature 1H and 13C NMR spectra of some N-tosyl diaza crown ethers have been obtained. They are discussed with respect to the preferred conformers of the crowns and the free energies of activation of the interconversional process of the large ring. Both the preferred conformers and the ring interconversional barriers have been found to be strongly dependent on the structure and the ring size of the studied compounds.
Yale,H.L.; Spitzmiller,E.R., Journal of Heterocyclic Chemistry, 1972, vol. 9, p. 911 - 918
作者:Yale,H.L.、Spitzmiller,E.R.
DOI:——
日期:——
Template synthesis of helicates of a [2 + 2] tetraimine macrocycle: crystal structure of the lead(II) perchlorate complex
作者:David E. Fenton、Ray W. Matthews、Mary McPartlin、Brian P. Murphy、Ian J. Scowen、Peter A. Tasker
DOI:10.1039/dt9960003421
日期:——
condensation of α,α′-bis(2-aminophenoxy)-o-xylene and pyridine-2,6-dicarbaldehyde produced mononuclear complexes of the same [2 + 2] cyclocondensation product L1 in the presence of divalent metal ions ranging in size from MnII to BaII. The origin of the apparent insensitivity of the synthesis to the metal-ion size lies in the ability of the resulting 34-membered macrocycle to adopt either of two distinct co-ordination