Low-dimensional compounds containing cyano groups: VIII. A spectral and thermal study of dicyanoargentates containing aliphatic diamine ligands

The synthesis, spectral and thermal properties of dicyanoargentates, namely Cu(tn)2Ag2(CN)4 (I) (tn = 1,3-diaminopropane), Cu8-xAgx(tn)3(CN)10 x=0.25 (II), Cu(pn)2Ag2(CN)4 (III) (pn = 1,2-diaminopropane) and Cu2(dabn)2(NH3)Ag4(CN)8·2H2O (IV) (dabn = 1,4-diaminobutane) are reported. All complexes were isolated from reaction mixtures containing K[Ag(CN)2], CuSO4 and N-donor ligands (tn, pn and dabn, respectively). Infrared spectra confirm the presence of characteristic functional groups and are consistent with the known structures of complexes (I), (III) and (IV). Thermal decompositions of complexes (I)–(IV) begin by endothermic liberation of ligand molecules followed by strong exothermic redox decomposition of the cyano groups. Comparison of the initial decomposition temperatures of complexes (I)–(IV) yields the following order of the thermal stability (IV)<(I)<(III)<(II).