Strong Ferromagnetic Exchange Interactions in Hinge-like Dy(O2Cu)2 Complexes Involving Double Oxygen Bridges

Two trinuclear isomeric compounds, [{(CuII(salpn))(Me(CO)Me)}2DyIII(NO3)3] (1) and [{CuII(salpn)}2DyIII(H2O)(NO3)3]·MeOH (2), along with one polymeric compound, {[{CuII(salpn)}2DyIII(NO3)3bpy]·MeOH·H2O}n (3), were synthesized using a metalloligand, [CuII(salpn)], where H2salpn and bpy stand for N,N′-bis(salicylidene)-1,3-propanediamine and 4,4′-bipyridine, respectively. Compounds 1 and 2 were selectively prepared with two solvents: the less polar acetone led to the exclusive crystallization of 1 with a transoid trinuclear architecture, while more polar solvent methanol provided sole construction of 2 with a cisoid trinuclear architecture. Compound 3 was prepared from 1 or 2 after bpy was introduced as a bridge. The Dy and Cu ions are doubly bridged with oxygen atoms, and the core DyO2Cu skeletons are characterized by different “butterfly angles” of 140.9(1)°, 147.1(19)°, and 142.4(2)° for 1, 2, and 3, respectively. We have examined the molecular structures and magnetic properties of 1–3 using high-frequen...