Structural and Spectroscopic Studies of [M((x)tu)₄]⁺ Systems (M = Cu, Ag; (x)tu = (substituted) Thiourea)

Abstract

Abstract In a low‐temperature redetermination of improved precision of the structure of [Cu(tu) 4 ] 2 (SiF 6 ) (‘tu’ = thiourea, SC(NH 2 ) 2 ), Cu–S range between 2.3173–2.3433(8), < > 2.336(11) Å, with S–Cu–S 92.72(3)–118.75(12)°. The first structure determination of a 1:4 adduct of a silver(I) salt with a (substituted) thiourea ligand is also reported, for silver(I) nitrate with ‘ethylenethiourea’, (‘etu’ = SC(NHCH 2 ) 2 ), as a monohydrate [Ag(etu) 4 ](NO 3 )·H 2 O, wherein Ag–S range between 2.544–2.637(2), < > 2.59(4) Å, S–Ag–S 87.88–117.57(7)°. Bands in the far‐IR spectra of these compounds are assigned to ν(MS) modes, and the frequencies are compared with those predicted by previously established correlations between ν(MS) and the M–S bond length d (MS) for copper or silver complexes with tu or etu ligands.