Conformational study of the macrocycle 1,4,7-trithiacyclononane in metal complexes

Abstract

Computational studies have been carried out on the macrocycle 1,4,7-trithiacyclononane [9]aneS₃ in the free state and in metal complexes. A range of metal complexes of [9]aneS₃ has been studied by molecular mechanics and good agreement has been obtained with experimental structural data. The macrocycle forms a series of octahedral complexes M([9]aneS₃)₂, with M–S bond lengths ranging between 2.241 Å for Fe^II to 2.725 Å for Ag^I. Changes in the geometry of the macrocycle upon binding to different metals in these complexes have been successfully modelled. Also studied were a range of less-symmetric structures containing this macrocycle and the reasons for the wide variations in conformation have been established.