Ferromagnetic exchange coupling in the linear, chloride-bridged cluster (cyclam)CoII[(μ-Cl)UIV(Me2Pz)4]2

A trinuclear cluster, (cyclam)Co[(μ-Cl)U(Me2Pz)4]2 (cyclam = 1,4,8,11-tetraazacyclotetradecane, Me2Pz− = 3,5-dimethylpyrazolate), has been synthesized through cleavage of [U(Me2Pz)4]2 by (cyclam)CoCl2. Magnetic susceptibility measurements indicate ferromagnetic coupling between the CoII and UIV centers. Estimates of the magnetic coupling strength are presented for (cyclam)Co[(μ-Cl)U(Me2Pz)4]2 (15 cm−1 < J< 48 cm−1) and compared with those calculated for the previously-reported cluster (cyclam)Ni[(μ-Cl)U(Me2Pz)4]2 (2.8 cm−1 < J < 19 cm−1).