Mono- and dinuclear silver(I) complexes of benzene- and pyridine-bearing 20-membered thiaoxaaza macrocycles

Two 20-membered penta- and hexadentate macrocycles containing one or two pyridine subunits, namely [20]aneNO(2)S(2) (L-1) and [20]aneN(2)O(2)S(2) (L-2), have been synthesized. Reaction of L-1 with silver(I) nitrate afforded a unique 2:2 (M:L) disilver(I) complex [mu(2)-Ag-2(L-1)(2)](NO3)(2) (1) in which two four-coordinate Ag atoms bridge two ligands to form a cyclic dimer. In contrast, an endo-dentate 1:1 monosilver(I) complexes [AgL2]X; [X = ClO4 (2) or PF6 (3)] which show isomorphous structures were obtained from the reactions of L2 with silver(l) salts. (C) 2007 Elsevier B.V. All rights reserved.