Crown thioether chemistry. The silver(I) complexes of trithia-9-crown-3, trithia-12-crown-3, and hexathia-18-crown-6

Abstract

The coordination chemistry of the three crown thioethers 1,4,7-trithiacyclononane (9S3), 1,5,9-trithiacyclododecane (12S3), and 1,4,7,10,13,16-hexathiacyclooctadecane (18S6) with Ag(I) has been investigated by structural and electrochemical methods. The bis complex (Ag(9S3){sub 2})(CF{sub 3}SO{sub 3}) contains a six-coordinate Ag(I) ion with Ag-S distances ranging from 2.696 (2) to 2.753 (1) {angstrom}. Chemical or electrochemical oxidation yields (Ag(9S3){sub 2}){sup 2+}, which has been studied by optical and EPR methods. The halide adducts (Ag(9S3)Cl) and (Ag(18S6)Br) both contain a tetrahedral AgS{sub 3}X core. In the former case, 9S3 coordinates in a tridentate fashion to yield a discrete, monomeric complex. In the latter, 18S6 provides two thioethers to one Ag(I) and a third to another to yield a polymeric chain. In (Ag(12S3))(CF{sub 3}SO{sub 3}) {center dot} MeCN, each Ag(I) ion coordinates to three thioether groups (one from each of three independent 12S3 molecules) as well as a CF{sub 3}SO{sub 3}{sup {minus}} counterion to yield distorted-tetrahedral geometry. In turn, the three ligand S atoms coordinate to different Ag(I) ions to generate a network structure. These results highlight the profound influence of ligand conformation on the structure and solution chemistry of their complexes. Crystal data for (Ag(9S3){sub 2}) (CF{sub 3}SO{sub 3}), (Ag(18S6)Br), (Ag(9S3)Cl), and (Ag(12S3))(CF{sub 3}SO{sub 3}) {centermore » dot} MeCN are reported.« less