Cobalt(II) coordination polymers constructed from bistriazole butane: Syntheses, structures, and properties

[Display omitted] •The counter anions can play an important role in preparing MOFs.•2D and 3D coordination polymers were isolated by using different cobalt(II) salts.•The conformational variation of btrb ligand is another influencing factor. Two new Co(II) complexes [Co0.5(btrb)1.5]·ClO4 (1) and [Co0.5(btrb)Cl] (2) (btrb=1,4-bis(1,2,4-triazol-1-y1) butane) have been synthesized and characterized by single crystal X-ray diffraction. Conformations of the flexible ligand btrb can be tuned as a result of changing the anions in the reaction system, which ultimately forms two novel framework structures. Complex 1 is a three dimensional framework, which has a threefold interpenetrating 3D α-Po cubic net network. 2 possesses 2D (4,4) net frameworks. Weak C–H⋯Cl hydrogen bonds reside among the 2D layers, which link the 2D layers to a 3D supramolecular architecture. For both 1 and 2, IR, elemental analysis and thermal stability have been carried out, and the conformational variation of btrb also has been discussed.