CRITERIA TO JUDGE PREORGANIZATION IN THE STUDY OF KNOWN AND THE DESIGN OF NEW THIOCROWN ETHERS

The structural preorganisation hypothesis has been considered in the l ight of current criteria and additional criteria have been proposed wh ich enable a priori design of organised macrocycles. Molecular dynamic s simulations have been performed on a series of 1,4,8,11-tetrathiacyc lotetradecane molecules, with no, one and two sets of gem-dimethyl sub stituents on the central carbons of their trimethylene bridges; these molecules are known to have stronger complexation with copper or nicke l as substitution increases. With the insights thus gained into the ef fect of the substitution, these studies are used to set new criteria w hich are then employed in the a priori design of novel conformationall y locked 1,4,7-trithiacyclononane ligands, with a set of endodentate s ulfurs, capable of co-ordinating to a metal ion simultaneously, withou t reorganisation.