Syntheses, structures, and photoluminescent properties of a series of zinc(ii)–3-amino-1,2,4-triazolate coordination polymers constructed by varying carboxylate anions

To explore the influence of different carboxylate ligands on the structures of metal–organic frameworks (MOFs), five novel Zn(II) coordination polymer compounds, namely, {[Zn(atz)(bia)]}n (1), {[Zn3(atz)3(tpa)3/2]}n (2), {[Zn2(atz)2(pda)]}n (3), {[Zn4(atz)2(btc)]·4H2O}n (4) and {[Zn2(atz)2(btec)]·H2O}n (5) have been successfully obtained by introducing various secondary auxiliary ligands in Zn(II)–L systems, characterized by elemental analysis, FT-IR, thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction (Hatz = 3-amino-1,2,4-triazolate, Hbia = benzoic acid, H2tpa = 1,4-terephthalic acid, H2pda = 1,4-benzenediacetic acid, H3btc = 1,3,5-benzenetricarboxylate, H4btec = 1,2,4,5-benzenetetracarboxylic). Compound 1 features a 2D layer with (4.82) topology, which is further stabilized by hydrogen bonds between the uncoordinated amino groups and uncoordinated oxygen atoms from bia ligands. Compound 2 exhibits a 3D 3,4-connected framework with {4.82.103}{4.82} topology, constructed from Zn(II) ions and μ3-atz ligand. Compound 3 displays a 3D 3,4-connected network with {4.6.8}{4.62.83} topology. Compound 4 possesses a 3D 9-nodal network with a point symbol of {4.8.9}2{4.82}{4.83.9.10}{5.8.9}4{5.82}. Compound 5 shows a 3D 3,4,4-connected framework with {4.82}4{42.83.10}2{84.102} topology. The diverse structures of these five complexes demonstrate that the skeleton of carboxylate ligands have a significant impact on the construction of MOFs. Moreover, the luminescence properties of complexes 1–5 were investigated in the solid state.