Ni(tn)2Ag2(CN)4 and Cu(tn)2Ag2(CN)4 (tn=1,3-diaminopropane): preparation, crystal structure, magnetic and spectral properties

Two new compounds, Ni(tn)2Ag2(CN)4 (tn=1,3-diaminopropane) (NTAC) and Cu(tn)2Ag2(CN)4 (CTAC), were prepared, and their structures were determined by single crystal X-ray diffraction. The structure of NTAC consists of individual centrosymmetric trinuclear molecules, in which the nickel atom is coordinated by two chelate-bonded tn molecules placed in the equatorial plane and two diacyanoargentate anions bonded via one μ-CN group. The trinuclear molecules interact together via short Ag⋯Ag contacts (3.2627(3)Å) forming a chain-like arrangement of molecules. The structure of CTAC is ionic and consists of [(tn)2Cuμ-NCAgCN]+ binuclear complex cations and two free crystallographically independent [Ag(CN)2]− anions. In CTAC, the silver atoms are close to each other, forming a bent chain-like Ag⋯Ag⋯Ag arrangement with alternating Ag⋯Ag distances of 3.2270(3) and 3.4166(3)Å. Experimental studies of the susceptibility and magnetization support the assumption about extremely weak magnetic correlations in both systems. The analysis of the NTAC susceptibility has revealed the significant effect of single ion anisotropy, ∣D∣/kB≈3K, which governs the magnetic behavior of this material below 6K.