Structure and magnetism of the first strictly dinuclear compound containing paramagnetic 3d and 5f metal ions. Major influence of the CuII ion coordination on the exchange CuII–UIV interaction

The dinuclear compound [CuL2(py)U(acac)2] has been synthesized by treating [Cu(H2L2)] with U(acac)4(L2=N,Nʹ-bis(3-hydroxysalicylidene)-2methyl-1,2-propanediamine) and shows the antiferromagnetic Cu–U interaction; the distinct magnetic behaviour of the trinuclear complexes [(CuL2)2U](antiferromagnetic) and [{CuL1(py)}U{CuL1}](ferromagnetic) revealed the major influence of the CuII ion coordination on the exchange interaction (L1=N,Nʹ-bis(3-hydroxysalicylidene)-2,2-dimethyl-1,3-propanediamine).