Two (3,10)-connected 2D networks based on pentanuclear metal clusters as building blocks

Self-assembly of a long, V-shaped 4,4'-sulfonyldibenzoato (sdba) ligand and metal salts in the presence of a heterocyclic aromatic ligand affords two (3, 10)-connected 2D networks: [Cd-5(mu(3)-OH)(2)(sdba)(4)(2,2'-bpy)(2)(H2O)(2)]center dot 2H(2)O (1) and [Mn-5(mu(3)-OH)(2)(sdba)(4)(2,2'-bpy)(2)(H2O)(2)]center dot H2O (2) (2,2'-bpy = 2,2'bipyridine). Their structures were determined by single-crystal X-ray diffraction analysis, and they were further characterized by elemental analysis, IR spectroscopy, and TG analysis. Compounds I and 2 are isostructural and represent the highest connected topology presently known for 2D nets. More interestingly, when the strong hydrogen bonds between layers are taken into account, the resulting net becomes a (3,12) -connected 3D network with complex (3(2).4),(3(8).4(22).5(24).6(10).7(2)) topology, which possesses the highest observed connectivity (twelve connectivity) known to date. The magnetic properties of compound 2 have been studied by measuring its magnetic susceptibility in the temperature range 2-300 K. The results indicate the existence of antiferromagnetic coupling within the pentanuclear manganese cluster. Furthermore, the luminescent properties of I are discussed. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).