Structure and magnetic properties of one carboxylate-bridged linear trinuclear [Ni3] and one paddle-wheel dinuclear [Cu2] cluster

Abstract Two carboxylate-bridged transition metal clusters, trinuclear [Ni3(CPA)6(bipy)2] (1) and dinuclear [Cu2(CPA)4(DMSO)2] (2), have been successfully prepared respectively based on mixed ligands of 4-chlorophenylacetic acid (HCPA) and 2,2’-bipyridine (bipy) or the single ligand of HCPA. Single crystal X-ray diffraction analyses reveal that complex 1 crystallizes in triclinic P-1 space group and has a structure of linear trinuclear [Ni3] cluster, and 2 crystallizes in monoclinic P21/n space group and includes a paddle-wheel dinuclear [Cu2] entity. The magnetic susceptibilities of 1 and 2 were quantitatively analyzed based on a linear trinuclear [Ni3] model with Hamiltonian Ĥ = -JŜ1Ŝ2-JŜ2Ŝ3 and a dimer [Cu2] model with Ĥ = -JŜ1Ŝ2, respectively, resulting in g = 2.18(1), J = -0.79(1) cm−1 for 1 and g = 2.19(1), J = -321(1) cm−1 for 2. These confirms that the neighboring spin centers both display antiferromagnetic coupling in 1 and 2.