Isomeric luminescent Zn(II) coordination polymers based on pyridinecarboxylate and 5-methyl-1H-tetrazole ligands

• Two new coordination polymers have been obtained through varying position-isomer ligands.
• Compound 1 and 2 have the same molecular formula but have different topological framework.
• These two compounds emit strong luminescence at room temperature.

Two new metal–organic frameworks, namely [Zn(nic)(mtz)]n (1) and [Zn(isonic)(mtz)]n (2) (Hnic = nicotinic acid, Hisonic = isonicotinic acid, Hmtz = 5-methyl-1H-tetrazole), have been obtained through the solvothermal reactions of Zn(NO3)2, Htmz and Hnic or Hisonic. Single crystal X-ray diffraction analysis reveals that compound 1 features a 2D layered structure with sql topology, which is further extended into a 3D supramolecular framework via weak CH…π interactions, and compound 2 is 2-fold interpenetrated 3D framework with dia topology. Luminescent investigation shows that both of them emit blue luminescence at room temperature.