Thiophenophane metal complexes. III. Preparation, X-ray structure, and properties of 2,5,7,10-tetrathia[12] (2, 5) thiophenophane, L, and [Ag2L2]2+, its dinuclear silver complex cation

Abstract

Preparations of the thiophenophane C12H18S5(L3), and its binuclear silver(I) complex cation [Ag2(L3)2]2+ are described. The 13C and 1H nmr spectra of L3 and the ir and fast atom bombardment mass spectra of the complex are reported. X-ray structures of L3 and [Ag2(L3)2](ClO4)2 have been determined. For L3: space group P21/n, a = 10.8866(2), b = 9.4419(4), c = 14.9608(2) Å, β = 97.132(1)°, Z = 4, Rf = 0.057, Rw = 0.045. For [Ag2(L3)2] [ClO4]2: space group P21/n,a = 9.2717(3), b = 19.8697(2), c = 10.2654(4) Å, β = 100.592(2)°, Z = 2, Rf = 0.036, Rw = 0.030. The effect of structure on the ligand's ability to form complexes is discussed. The centrosymmetric dinuclear cation has slightly distorted trigonal bipyramidal coordination geometry about each silver. The silver atoms are linked by one bridging thioether sulfur from each ligand. The remaining three sites on each silver are occupied by two terminal thioether sulfurs from one ligand molecule and one from the other ligand molecule. The complex is remarkably stable photochemically and chemically but under certain specific conditions reacts with loss of ligand. This stability is discussed with respect to structure. Keywords: binuclear silver(I) thiophenophane complex.