Unprecedented binodal (7,9)-connected network based on distinct tricobalt(II) clusters: structure, topology and cooperative magnetism

A new Co(II)-based coordination polymer, [{Co-3(ina)(7.5)(mu(3)-O)}{Co-3(ina)(2.5)(mu(3)-OH)(mu-OH) (C2H5OH)=(H2O)(2)}(3)]NO3 center dot 3C(2)H(5)OH center dot 24H(2)O (1, also denoted as MCF-39), has been synthesized from the solvothermal reaction of cobalt(II) nitrate and the ligand isonicotinic acid (Hina) with the presence of hmq (2-(hydroxymethyl)-quinolin-8-ol) as a necessary additive. The crystal structure of 1 consists of the 7- and 9-connected trinuclear clusters, and exhibits the first highly-connected binodal network with (3(4)center dot 4(9)center dot 5(6)center dot 6(2))(3)(3(6)center dot 4(15)center dot 5(15)) topology. Magnetic studies show that the spin canting and spin-glass-like behaviours were found in 1, and the cooperative effect among intra- and inter-trimer could greatly influence the bulk magnetic behaviour of the three-dimensional (3D) framework.