Two new pH-controlled coordination polymers constructed from an asymmetrical tricarboxylate ligand and Zn-based rod-shaped SBUs

• Two rod packing coordination polymers were synthesized by controlling the amount of NaOH.
• An unprecedented 1D rod-shaped Zn-chain based on Zn5(COO)6 units is first obtained.
• In solid state, both complexes exhibit good emission at room temperature.

Two new 3D coordination polymers, [Zn3(L)2(H2O)4]·H2O (1) and [Zn5(μ3-OH)4(L)2(H2O)2] (2) (H3L = 3-(2′,5′-dicarboxylphenyl)benzoic acid), have been synthesized under hydrothermal conditions by adding different amounts of NaOH. Structural analyses show that both of them contain 1D inorganic Zn(II)-chains as rod-shaped secondary building units (SBUs) but they are in different forms. The rod-shaped Zn(II)-chain of 1 is only Zn-carboxylate chain, while the one in 2 is formed by the independent Zn5(COO)6 clusters connected by hydroxyl oxygen. Furthermore, the thermal and luminescent properties of both compounds have been studied.

Two new coordination polymers based on two different rod-shaped SBUs have been synthesized by controlling the amount of NaOH added. Particularly, an unusual rod-shaped Zn-chain is formed by the independent Zn5(COO)6 clusters connected by OH− groups. This work presents that NaOH not only regulates the pH but also can participate in coordination.Figure optionsDownload as PowerPoint slide