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-trithia cycloundec-9-yne (L(I)) to Ag-I results in a change of ligand conforma tion from exodentate in the free ligand to endodentate in the coordina ted ligand implying involvement of the thioether functionalities in co ordination. Participation of the alkyne linkage in coordination is les s certain and a polymeric structure is suggested in the solid state. R eaction 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 e ta(3)-L(I). Similar studies with Cu-I and Hg-II showed a reduced tende ncy for thioether coordination reflected in a reduced denticity of L(I ). Studies with a range of dithiacycloalkynes and a tetrathiacyclodiyn e show that Ag+ and Cu+ can be successfully coordinated by ligands con taining a combination of two thioether donors and one alkyne. (C) 1997 Elsevier Science Ltd.