Making 3d–4f hexanuclear clusters from heterotrinuclear cationic building blocks

The syntheses and crystal structures of two new hexanuclear complexes are reported: [{(LCuII(ONO2))(LCuII(H2O))NdIII}2(μ-C2O4)](NO3)2 · 6H2O (1) and [{(LNiII(H2O))(N(CN)2)}2PrIII}2(ONO2)](OH) · 2H2O · 3CH3CN (2) (L is the dianion of the Schiff-base resulted from the 2:1 condensation of 3-methoxysalyciladehyde with 1,3-propanediamine). Compounds 1 and 2 were obtained by connecting heterotrinuclear cationic complexes [{LMII}2LnIII]3+ with oxalato or nitrato linkers. The structure of the complex cation in 1 shows two almost linear trinuclear [Cu2Nd] moieties which are linked by a bis-chelating oxalato bridge between the neodymium ions. The hexanuclear cationic moiety in 2 is built up of two heterotrinuclear [Ni2Pr] units that are linked by a nitrato group bridging two praseodymium(III) ions. The spectroscopic (FTIR, UV–Vis) and magnetic properties of 1 and 2 have been investigated.