Mixed-ligand strategy affording two 6-connected 3-fold interpenetrated metal-organic frameworks with binuclear Co-2(II)/Ni-2(II) subunits: Synthesis, crystal structures and magnetic properties

摘要

Two 6-connected (6-c) edge-transitive nets, namely, [Co-2(2,6-ndc)(2)(4-bpdb)center dot 2CH(3)OH center dot 2H(2)O](n), (1), and [Ni-2(2,6-ndc)(2)(4-bpdb)center dot(H2O)(3)center dot 2DMF](n) (2) (2,6-H(2)ndc = 2,6-naphthalenedicarboxylic acid, 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene), were synthesized under solvothermal conditions. The structure of 1 manifests a threefold interpenetrated 3D pcu topology based on paddle-wheel [Co-2(mu(2)-eta(1):eta(1)-COO)(4)] dimers. The structure of 2 possesses a three-fold interpenetrated 3D acs topology based on [Ni-2(mu(2)-OH2)(mu(2)-eta(1):eta(1)-COO)(2)(eta(1)-COO)(2)] dimeric units. Magnetic analyses indicate that both two compounds show weak antiferromagnetic interactions within binuclear Co-2(II) and Ni-2(II) units.