Hydrogen‐Bonded Network and Layered Supramolecular Structures Assembled from ClO4− Counterions with Unprecedented Monomeric [AgL2]+ and Chain Polymeric [AgL2]nn+ Complex Cations (L = Thioamide or Thiourea‐Like Ligands)

Abstract

AbstractThe complexes [Ag(etu)2]ClO4 (1) and [{Ag(py2tH)2}(ClO4)(H2O)0.5]n (2) have been obtained from the reactions of AgClO4 with the corresponding thioamide ligands (etu = imidazolidine‐2‐thione; py2tH = pyridine‐2‐thione). Complex 1, consisting of centrosymmetric monomeric [Ag(etu)2]+ cations and ClO4− counterions, constitutes the first bis[thio(mono‐ or di)amide] complex (M = Cu, Ag) known thus far to possess a linear MS2 mononuclear core. Component ions behave in the crystal structure as complementary partners, with all four N−H groups of each [Ag(etu)2]+ cation and all four oxygen atoms of each ClO4− anion involved in N−H···O−Cl hydrogen bonding associations. This leads to the assembly of a three‐dimensional supramolecular network. Complex 2, whose previously reported structure has been redetermined with higher precision, contains catena‐[Ag(py2tH)2]nn+ polymeric cations consisting of linear chains of linked Ag2(μ‐S)2 rings, with distorted tetrahedral AgS4 centres. Supramolecular association through N−H···O−Cl, N−H···O(water) and Cl−O···H−O−H···O−Cl hydrogen bonding, where all N−H groups and H2O molecules and only one or two oxygen atoms of each ClO4− anion are involved, leads to the formation of a two‐dimensional layered supramolecular structure. A correlation of some stereochemical parameters and a simple qualitative sulfur‐bridge bonding model has been developed for 2 and other related thioamide complexes containing M2(μ‐S)2 rings or M−S−M′ single bridges. For these structural units, suitable ranges of tilt and twist dihedral angles have been estimated and assigned to different bonding types. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)