NMR spectroscopic and molecular modelling studies of the solution structure and complexational behaviour of some bis(benzocrown ether)s
- Structural information about the bis(benzo crown ether)s I-VI and their complexes with alkali metal cations was deduced from the 13C NMR chemical shifts, the salt-induced 1H and 13C chemical shifts and the vicinal 1H,1H coupling constants. Especially the isomerism with respect to the amide O=C - NH bonds and imine fragments were assigned by various useful NMR parameters ( C=O, 1JN,H, 1JC,H) and proved to be E,E-anti,anti. Furthermore, stereochemical information about preferred conformations about flexible bonds was obtained from 2D ROESY NMR experiments. The complex formation (2:1 complexes and sandwich-like 1:1 complexes, respectively) were determined also by 23Na NMR spectroscopy. The conformational study of the crown ethers was accompanied and corroborated by molecular dynamics and quantum chemical calculations.
Author details: | Manuela Grotjahn, S. Lehmann, Ines Aurich, Hans-Joachim Holdt, Erich KleinpeterORCiDGND |
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Publication type: | Article |
Language: | English |
Year of first publication: | 2001 |
Publication year: | 2001 |
Release date: | 2017/03/24 |
Source: | Journal of physical organic chemistry. - 14 (2001), 1, S. 43 - 51 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
Peer review: | Referiert |