Organic Cation Templated Synthesis of Three Zinc–2,5-Thiophenedicarboxylate Frameworks for Selective Gas Sorption

Three anionic Zn­(II)–organic frameworks with 2,5-thiophenedicarboxylate ligand have been synthesized solvothermally. They exhibit different 3D net topologies but all contain trinuclear [Zn₃(COO)₈] building units. Compound 1 shows an 8-connected bcg net just based on [Zn₃(COO)₈] nodes, while compound 2 displays an 8-connected bcu net based on two similar [Zn₃(COO)₈] nodes. Interestingly, compound 3 represents a novel (4,8)-connected flu net based on the trinuclear nodes [Zn₃(COO)₈] and the binuclear nodes [Zn₂(COO)₄]. Gas sorption measurements indicate that the desolvated host 1-ht exhibits permanent porosity with Langmuir surface area of 630.5 m²·g^–1 and a H₂ uptake of 109.5 cm³·g^–1 at 77 K and 1 atm, as well as a selective sorption of CO₂ over N₂ at 0 °C and ambient pressure.