Criteria to judge preorganisation in the study of known and the design of mew thiocrown ethers

Abstract

The structural preorganisation hypothesis has been considered in the light of current criteria and additional criteria have been proposed which enable a priori design of organised macrocycles. Molecular dynamics simulations have been performed on a series of 1,4,8,11-tetrathiacyclotetradecane molecules, with no, one and two sets of gem-dimethyl substituents on the central carbons of their trimethylene bridges; these molecules are known to have stronger complexation with copper or nickel as substitution increases. With the insights thus gained into the effect of the substitution, these studies are used to set new criteria which are then employed in the a priori design of novel conformationally locked 1,4,7-trithiacyclononane ligands, with a set of endodentate sulfurs, capable of co-ordinating to a metal ion simultaneously, without reorganisation.