Three hetero-tri-spin Ln2CuNIT complexes based on a 1-methyl-3-pyrazole nitronyl nitroxide radical: Syntheses, structures and magnetic properties

Three novel 2p-3d-4f complexes [Ln2Cu(hfac)8(1-Me-3-NIT-Pyz)2]·CH2Cl2 were obtained based on the 1-methyl-3-pyrazole radical as isomorphic trinuclear hetero-spin complexes. DC and AC magnetic studies showed different magnetic behaviors. With the help of spin Hamiltonian calculations and MAGPACK program, it is concluded that there exist ferromagnetic couplings not only between the GdIII ion and the NIT radical but also between the CuII ion and the NIT radical, with J1 = 4.2(1) and J2 = 23.6(1) cm−1, respectively. The fitted antiferromagnetic constant (J3) between radical and radical is −6.7(1) cm−1 in 1. The Tb and Dy complexes show no distinct frequency dependence.