The crystal structures of the cobalt(II) metal–organic frameworks or coordination networks of [Co(pdb)(DMF)] and [Co₂(pdi)(DMF)₃]·2(DMF)·H₂O (H₂pdb = 3,3′-(phenazine-5,10-diyl)dibenzoic acid; H₄pdi = 5,5′-(phenazine-5,10-diyl)diisophthalic acid; DMF = N,N-dimethylformamide) were synthesized solvothermally from cobalt(II) nitrate and the free acid of the linker in DMF. Systematic solvothermal screening demonstrated strong metal- and counterion-dependent framework formation, as crystalline coordination polymers were obtained exclusively from cobalt(II) nitrate, whereas other metal salts and cobalt(II) chloride or sulfate produced no crystalline materials. In catena-[(N,N-dimethylformamide)-μ₄-3,3′-(phenazine-5,10-diyl)dibenzoate-cobalt(II)], [Co(pdb)(DMF)], the Co₂ units, acting as secondary building units, are coordinated by four carboxylate groups from four linkers in a paddle-wheel arrangement, giving a three-dimensional (3D) network with cds (or CdSO₄) topology, in which the wide openings are filled by two symmetry-related nets to form a threefold interpenetrated structure. In catena-[tris(N,N-dimethylformamide)-μ₈-5,5′-(phenazine-5,10-diyl)diisophthalate-dicobalt(II)] bis(N,N-dimethylformamide) hydrate, [Co₂(pdi)(DMF)₃]·2(DMF)·H₂O, there are two different Co atoms, of which only Co₂ is connected to each of the four carboxylate groups of the tetracarboxylate linker and, thus, is responsible for 3D network formation. The network topology in [Co₂(pdi)(DMF)₃] is pts (or platinum(II) sulfide) when taking the Co₂ atom as a tetrahedral node and the linker as a square-planar fourfold node; however, this arrangement is inverse to the common square-planar metal and tetrahedral linker nodes found in PtS and most pts topologies.

The crystal structures of the cobalt(II) metal-organic frameworks or coordination networks [Co(pdb)(DMF)] and [Co₂(pdi)(DMF)₃]·2(DMF)·H₂O (H₂pdb = 3,3′-(phenazine-5,10-diyl)dibenzoic acid, H₄pdi = 5,5′-(phenazine-5,10-diyl)diisophthalic acid, DMF = N,N-dimethylformamide) were synthesized solvothermally from cobalt(II) nitrate and the free acid of the linker in DMF. In catena-[(N,N-dimethylformamide)-μ₄-3,3′-(phenazine-5,10-diyl)dibenzoate-cobalt(II)], [Co(pdb)(DMF)], the Co₂ handles as secondary building units are surrounded by four carboxylate groups from four linkers in a paddle-wheel arrangement giving a three-dimensional (3D) network with cds (or CdSO₄) topology in which the wide openings are filled by two symmetry related nets to a threefold interpenetrated structure. In catena-[tris(N,N-dimethylformamide)-μ₈-5,5′-(phenazine-5,10-diyl)diisophthalate-dicobalt(II)] bis(N,N-dimethylformamide) hydrate, [Co₂(pdi)(DMF)3]·2(DMF)·H₂O, there are two different Co atoms from which only Co₂ is connected to each of the four carboxyl groups of the tetracarboxyl linker and, thus, is responsible for the 3D network formation. The network topology in [Co₂(pdi)(DMF)₃] is pts (or platinum(II) sulfide) when taking the Co₂ atom as a tetrahedral and the linker as a square-planar fourfold node which is, however, inverse from the common square-planar metal and tetrahedral linker nodes in PtS and most pts topologies.