Self-Assembly of a Dodecanuclear [Ni-12] Wheel

Self-assembly of nickle acetate and N,N '-di[1-(2-hydroxyphenyl)-ethylidene]hydrazone (H2L) ligand in a 2 : 1 ratio in DMF and methanol afforded a dodecanuclear wheel-like coordination cluster: [Ni12L6(OAc)(6)(HCOO)(6)(DMF)(6)] . 4DMF . 5H(2)O (1), in which the formate ions were likely in situ originated from the oxidation of methanol molecules and each deprotonate ligand (L2-) adopting the mu(4)-eta(2),eta(1),eta(1),eta(2) coordination mode with a large C=N-N=C torsion angle of 94.1 degrees ligates four different Ni(II) ions. Magnetic study revealed that 1 showed the long-range antiferromagnetic order with the Neer temperature of 9.0 K while the intracluster interaction between the neighboring Ni centers is alternately ferro- and antiferromagnetic (J=+5.0/-9.2 K in the one J), mainly depending on the oxo-bridging angles.