A new ZnII coordination polymer based on 4‐(pyridin‐4‐yl)benzoic and formic acids: in‐situ synthesis, crystal structure and luminescence properties

The title compound, poly[(μ2‐formato‐κ3O,O′:O)[μ2‐4‐(pyridin‐4‐yl)benzoato‐κ3N:O,O′]zinc(II)], [Zn(C12H8NO2)(HCOO)]n, has been synthesized in situ and characterized by thermogravimetric analysis (TGA) and single‐crystal and powder X‐ray diffraction analyses. The polymer contains two independent structural units in the asymmetric unit. These are constructed from Zn2+ ions, 4‐(pyridin‐4‐yl)benzoate (4‐pbc) bridges and in‐situ‐generated formate ligands, forming two similar two‐dimensional (2D) layer structures. These similar 2D layers are arranged alternately and are linked with each other by dense C—H…O hydrogen bonds to generate a three‐dimensional (3D) supramolecular framework. The crystal is pseudomerohedrally twinned about [201]. Compared with free 4‐Hpbc, the polymer exhibits a red shift and significantly enhanced solid‐state luminescence properties. Poly[(μ2‐formato)[μ2‐4‐(pyridin‐4‐yl)benzoato]zinc(II)] contains two independent structural units in the asymmetric unit, forming two similar two‐dimensional (2D) layer structures. These similar 2D layers are arranged alternately and are linked with each other by dense C—H…O hydrogen bonds to generate a three‐dimensional supramolecular framework.