Coordination of d(10)-metal cations by thiacycloalkynes

A range of complexes has been prepared by reaction of thiacycloalkynes with Ag-I, Cu-I and Hg-II cations and cationic MPR(3) (M = Ag, Cu, Hg) fragments. H-1 NMR studies reveal that coordination of 1,4,7-trithiacycloundec-9-yne (L(I)) to Ag-I results in a change of ligand conformation from exodentate in the free ligand to endodentate in the coordinated ligand implying involvement of the thioether functionalities in coordination. Participation of the alkyne linkage in coordination is less certain and a polymeric structure is suggested in the solid state. Reaction of AgSbF6 with L(I) and PPh(3) or PMe(2)Ph afforded complexes in which the silver is coordinated by a phosphine and an endodentate eta(3)-L(I). Similar studies with Cu-I and Hg-II showed a reduced tendency for thioether coordination reflected in a reduced denticity of L(I). Studies with a range of dithiacycloalkynes and a tetrathiacyclodiyne show that Ag+ and Cu+ can be successfully coordinated by ligands containing a combination of two thioether donors and one alkyne.