Issue 10, 1994

A detailed study defining the extent of preorganization of an aza macrocycle containing the phenyldinaphthomethane subunit (a three bladed propeller) using dynamic NMR and molecular dynamics

Abstract

The aza-propeller crown 4,7,10-tritosyl-4,7,10-triaza-1,13-dioxacyclooctadecane 1 has been examined by variable temperature 13C NMR studies, and the movement of each segment of the molecule (ArOCCN, NCCN, propeller) was determined kinetically. Several sets of coalescences were found to occur at the same activation energy, which was also that found for the flip of the propeller segment. This movement of the macrocycle as a whole is a relatively slow process (ms scale) compared to the torsional movements round the crown ether ring (ps scale). These torsional movements were explored by molecular dynamics (MD) modelling; the macrocyclic ring is mobile when simulated at 200 K. The tosyl groups are in permanent motion although none twists by more than a few degrees round the N–S torsion. The segments next to the propeller (which are both gauche in the crystal structure) converted from gauche to anti, while the TsNCCNTS segments remained anti throughout.

Article information

Article type
Paper

J. Chem. Soc., Perkin Trans. 2, 1994, 2145-2148

A detailed study defining the extent of preorganization of an aza macrocycle containing the phenyldinaphthomethane subunit (a three bladed propeller) using dynamic NMR and molecular dynamics

P. J. Cooper, M. N. S. Hill and J. C. Lockhart, J. Chem. Soc., Perkin Trans. 2, 1994, 2145 DOI: 10.1039/P29940002145

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements