The synthesis and crystal structures of the amide NS3 macrocycle L-1, and the silver complexes [Ag(L-1)](n)[CF3SO3](n) and of [Ag(L-2)](2)[CF3SO3](2)(where L-1 = 9-oxo-1,4,7-trithia-10-azacyclododecane and L-2 = 7-oxo-2,5,11-trithia-8-azatetradecane-[12]-orthobenzenophane).

The free macrocycle, L-1 was prepared by caesium carbonate promoted ring cl osure of the free NS3 dithiol with dibromoethane and crystallised from CDCl 3. The X-ray structure shows exodentate orientation of the sulfur and nitro gen atoms. Reaction of silver triflate with 1 molar equivalent of L-1 in ch loroform/methanol affords the homoleptic polynuclear species [Ag(L-t)](n)() that shows (3 + 1) thioether coordination to each of the silver centres. with one sulphur donor of each macrocycle bridging between metal centres. T he macrocycle is coordinated as a neutral ligand, with ligation occurring o nly through the sulphur atoms and the amide nitrogen remaining protonated a nd uncoordinated. Reaction between silver triflate and L-2 affords the dime ric species [AgL2](2)(2+) with coordination by the three sulphur donor atom s to the silver centre. Tetrahedral coordination is completed by an unexpec ted Ag-C interaction with the aromatic backbone. In both metal complexes, n o interaction is observed between the silver atom and the amide nitrogen. ( C) 1998 Elsevier Science Ltd. All rights reserved.