New macrocyclic ligands. XIV. Synthesis and X-ray structures of potentially pentadentate ligands incorporating non-symmetrically arranged N 4 S-, N 3 OS-, N 2 O 2 S- and N 2 S 2 O-heteroatoms.

Abstract

The synthesis and characterization of new mixed-donor macrocyclic ligands incorporating nitrogen, sulfur and/or oxygen heteroatoms are described. The new 17- or 18-membered macrocyclic rings contain unsymmetrical arrangements of their heteroatoms in contrast to related, previously reported rings in which the donor sets are arranged symmetrically. The X-ray structures of the 17-membered rings incorporating N4O- and N4S-donor sets are presented.