title: Application of RDC enhanced NMR spectroscopy in structural analysis of thiacalix[4]arene derivatives.
abstract: Thiacalix[4]arene spirodienone was rearranged into the corresponding phenoxathiin-based macrocycle. Alkylation of this inherently chiral system to achieve its immobilization led to a mixture of only two (out of four theoretically possible) stereoisomers. As standard NOE and dynamic NMR experiments did not lead to unambiguous determination of the structures we applied the Residual Dipolar Coupling constant (RDC) method. Poly-γ-ethyl-l-glutamate (PELG) and poly-γ-benzyl-l-glutamate (PBLG) were found to be easily applicable lyotropic liquid crystalline alignment media for the conformational analysis of thiacalixarene derivatives. Using these media the 1,2-alternate and the partial cone conformations were determined unequivocally.
authors.affiliation: Laboratory of NMR Spectroscopy, University of Chemistry and Technology, Prague (UCTP), Technická 5, 166 28 Prague 6, Czech Republic.
authors.forename: L
authors.initials: L
authors.lastname: Vrzal
authors.forename: M
authors.initials: M
authors.lastname: Kratochvílová-Šimánová
authors.forename: T
authors.initials: T
authors.lastname: Landovský
authors.forename: K
authors.initials: K
authors.lastname: Polívková
authors.forename: J
authors.initials: J
authors.lastname: Budka
authors.forename: H
authors.initials: H
authors.lastname: Dvořáková
authors.forename: P
authors.initials: P
authors.lastname: Lhoták