Structural and spectroscopic studies of some adducts of silver(I) salts with ethylenethiourea

Abstract

Syntheses, single crystal X-ray structural and spectroscopic characterizations are described for a variety of adducts of silver salts with ethylenethiourea (etu). Ag2SO4/etu (1:6) is isomorphous with its previously studied copper(I) counterpart, the [Ag(S-etu)3]+ species disposed with their silver atoms on crystallographic 3-axes, one of the two independent cations being slightly perturbed by a distant O-sulfate approach along that axis. In AgCl/etu (1:3), the silver atom is in a four-coordinate ClAgS3 environment, while AgNO3/etu (1:3) takes the form [(etu)2Ag(µ-S-etu)2Ag(etu)2](NO3)2. AgBr/etu (1:2) is binuclear [(etu)2Ag(µ-Br)2Ag(etu)2)], unlike its previously studied copper counterpart, which is [(etu)BrCu(µ-S-etu)2CuBr(etu)]. AgCl/etu (4:6) is an interesting ionic polymer [ClAg4(etu)6](∞|∞)Cl3, containing a novel one-dimensional polymeric cation. Bands in the far IR spectra of these compounds are assigned to v(AgS) and v(AgX) (X = halogen) modes, and a correlation between v(AgS) and the Ag–S bond length d(AgS) is established for silver complexes involving the etu ligand.Key words: silver, sulfur ligands, X-ray crystal structure, coordination chemistry, complexes.