A novel pillared-layer-type porous coordination polymer featuring three-dimensional pore system and high methane storage capacity

Solvothermal reaction of Zn(NO3)(2), 4-(1H-pyrazol-4-yl)pyridine (Hpypz) and 1,3,5-benzenetricarboxylic acid (H(3)btc) in N,N-dimethylacetamide (DMA) produced a new porous coordination polymer [Zn-5(pypz)(4)(btc)(2)] (1). Single-crystal X-ray diffraction study of 1 showed that deprotonated pypz(-) ligands served as 1,2,4-triazolate-like ligands, linking Zn(II) ions to form porous two-dimensional (2-D) sql-a layers {Zn(pypz)}(+), which were further connected by eight-legged pillars {Zn-2(btc)(4)(H2O)(2)}(8-) based on the typical paddlewheel dinuclear Zn2(RCOO)(4)(H2O)(2) cluster to form a novel type of non-interpenetrated pillared-layer framework with 3-D intersecting pore system and large pore volume. Gas sorption measurements revealed that 1 possesses large BET surface area of 2061 m(2) g(-1) and very high methane total uptake of 245 cm(3)(STP) cm(-3) at 298 K and 65 bar.