Highly-connected, porous coordination polymers based on [M4(μ3-OH)2] (M = CoII and NiII) clusters: different networks, adsorption and magnetic properties

Two new 3D coordination polymers based on tetranuclear clusters, {[Co-4(ina)(5)(mu(3)-OH)(2)(H2O)(EtOH)]-NO3 center dot 2EtOH center dot 4H(2)O}(n) (1) (Hina = isonicotinic acid) and {[Ni-4(ina)(5)(mu(3)-OH)(2)(EtCOO)]center dot 6EtOH center dot 2H(2)O}(n) (2), were obtained by the solvothermal reactions from Hina and different metal salts. The [M-4(mu(3)-OH)(2)] cores act as 7- and 9-connected nodes and are extended through ina linkers to highly-connected frameworks with vmr net for 1 and bct-9-P2(1)/c net for 2. Both the desolvated frameworks display effective gas sorption capacities of N-2 and H-2 with Langmuir surface areas of 546 and 917 m(2) g(-1) for 1 and 2, respectively. Magnetic studies show spin canting and spin-glass behaviours with T-g = 6.0 and 15.0 K for 1 and 2, respectively. The intra- and inter-tetramer coupling interactions and cooperative magnetic correlation greatly influence the bulk magnetic behaviours in this system.