Metal-organic frameworks (MOFs) are a class of materials representing coordination polymers based on two main components: the organic linkers and the metal centres or clusters that are connected to each other by coordination bonds, together with other intermolecular interactions generating 2D or 3D extended structures [1]. Here we report the synthesis of two new 1D and 2D MOFs of cobalt(II) and nickel(II) using 4,4'-bis(1H-imidazol-1-yl)biphenyl (BIBP) and 1,2,3-benzenetricarboxylic acid (H3BDC) as ligands. The change of metal ion caused differences in compounds’ structures. The reaction with nickel(II) ions results in a 1D polymer of the general formula {[Ni3(BIBP)3(BTC)2(H2O)4]∙2H2O}n. Each metal center is six-coordinated and has a distorted octahedral geometry. Every 2 carboxylic groups of the acid displays monodentate binding mode through a μ2-oxo bridge. Polymer chain extension is blocked by the 2 water molecules that complete the octahedral surrounding of the 2 marginal nickel(II) ions. This fact is not seen in cobalt compound which is a 2D polymer with general formula [Co3(BIBP)2(BTC)2(H2O)2]n. The 3 cobalt(II) ions of coordinative node have different environment: the central ion is six-coordinated with octahedral arrangement, the other 2 ions are five-coordinated with a distorted trigonal bipyramidal surrounding. Two monodentate carboxylic groups connect 2 cobalt(II) ions of neighboring structural units, while the third carboxylic group acts as a chelate-bridge for marginal cobalt(II) ions. BIBP units serve as pillars to join the chain building a two-dimensional layer (Fig. 1).figureFig. 1. The coordinating nodes and architecture of the polymers {[Ni3(BIBP)3(BTC)2(H2O)4]∙2H2O}n (left) and [Co3(BIBP)2(BTC)2(H2O)2]n (right). Sorption and thermal properties of the compounds have been investigated.