Four three-dimensional metal–organic frameworks assembled from 1H-tetrazole: Synthesis, crystal structures and thermal properties

Formation of a N/O/F-Rich and Rooflike Cluster-Based Highly Stable Cu(I/II)-MOF for Promising Pipeline Natural Gas Upgrading by the Recovery of Individual C3H8 and C2H6 Gases

“…With four Cu­(II) ions being coordinated by both tetrazolyl groups and carboxyl groups, and two Cu­(I) ions being only coordinated by tetrazolyl groups, a new C 2 -symmetric rooflike [Cu­(II) 4 Cu­(I) 2 (COO) 4 (tetrazolyl) 6 ] cluster was formed with two Cu­(I) ions being located at its two diagonal corners (Figures a, S1, and S2). Different from the cluster of the reported nonporous rooflike [Cu­(II) x Cu­(I) y (tetrazolyl) z ] (2 x + y − z )+ cluster-based MOFs, − four carboxyl groups substituting a part of tetrazolyl groups were found in the rooflike cluster of SNNU-Bai68. With two Cu­(I) ions at the diagonal corners from two adjacent centrosymmetric rooflike clusters connected by two adjacent N heteroatoms in one tetrazolyl group through their coordinations, the 1D Cu–N/O chain secondary building block (SBB) along the c- axis was generated with a high density of potential adsorptive sites (Figures a, S2, and S3).…”

“…With two Cu­(I) ions at the diagonal corners from two adjacent centrosymmetric rooflike clusters connected by two adjacent N heteroatoms in one tetrazolyl group through their coordinations, the 1D Cu–N/O chain secondary building block (SBB) along the c- axis was generated with a high density of potential adsorptive sites (Figures a, S2, and S3). Furthermore, with the 1D chain SBB linked by the FTZB 2– ligands through the tetrazolyl group and the carboxyl group, respectively, along the ( a + b ) and ( a – b ) directions, the 3D framework of the N/O/F-heteroatom-rich and a rooflike [Cu­(II) 4 Cu­(I) 2 (COO) 4 (tetrazolyl) 6 ] cluster-based MOF (SNNU-Bai68) was successfully constructed to be porous, which served as a multiple heteroatom-rich and curved-surface-shaped SBU-based ultra-microporous MOF and was the first porous MOF based upon such a rooflike [Cu­(II) x Cu­(I) y (tetrazolyl) z ] (2 x + y − z )+ cluster. − …”

“…Due to different polarities, dynamic diameters, and shapes of C 3 H 8 , C 2 H 6 , and CH 4 gas molecules, MOFs with polar pore surfaces, suitable pore sizes (to be around the diameter of the C 3 H 8 gas molecules), and unique pore shapes (which could induce a suitable pore size, , the “pocket” or “corner” as the gas adsorptive site, ,, the special cage as the “trap” for gas molecules, − etc.) may have promising potential for the highly efficient separation of C 3 H 8 , C 2 H 6 , and CH 4 gases through different synergistic H-bonds or other van der Waal interactions between the frameworks and gas molecules. − By a survey of the Cambridge Structural Database and the open literature, the N-heteroatom-rich rooflike [Cu­(II) x Cu­(I) y (tetrazolyl) z ] (2 x + y − z )+ cluster being constructed by the functionalized tetrazolyl group has attracted our attention as a multiple heteroatom-rich and curved-surface-shaped inorganic cluster, − which has only been observed in several nonporous MOFs. − Moreover, from the organic ligands containing both N-heterocyclic groups and carboxyl groups, we have synthesized several MOFs with some special structural features and high performances for the storage and separation of environment- and energy-relevant gases. − Herein, based upon 3-fluoro-4-(2- H -tetrazol-5-yl)-benzoic acid (H 2 FTZB), a N/O/F heteroatom-rich and rooflike [Cu­(II) 4 Cu­(I) 2 (COO) 4 (tetrazolyl) 6 ] cluster-based ultra-microporous tsi -MOF, [Cu 3 (HFTZB)­(FTZB) 2 ·DMF]· x Guest (SNNU-Bai68, SNNU-Bai = Shaanxi Normal University Bai’s group), was afforded as a multiple heteroatom-rich and curved-surface-shaped cluster-based ultra-microporous MOF and was the first porous MOF based upon such a rooflike [Cu­(II) x Cu­(I) y (tetrazolyl) z ] (2 x + y − z )+ cluster. Very interestingly, it exhibits the most promising balance of high gas adsorption uptakes at 0.01, 0.03, and 0.05 bar, high C 3 H 8 /CH 4 , C 3 H 8 /C 2 H 6 , and C 2 H 6 /CH 4 adsorption selectivities, moderate adsorption enthalpies, and high water and chemical stability for the pipeline NG upgrading by C 3 H 8 and C 2 H 6 recovery, in comparison with those of many reported representative MOFs for the selective C 3 H 8 and C 2 H 6 gas adsorptions over CH 4 gas.…”

Energetic Coordination Polymers Based on Copper Furazans and 1,2,3-Triazoles: Tuning the Oxygen Balance with Nitramino Functionalities

“…As we can see in Figure , in comparison to the energetic complexes in the literature − (see details in Table S5), the oxygen balance as well as contents of nitrogen and oxygen atoms of Cu­(DNAF)­(NH 3 ) 3 , Cu­(DNAF)­(H 2 O) 3 , Cu­(ANFZ) 2 (H 2 O) 5 , and Cu 2 (TA) 2 (H 2 O) 6 remain at a relatively higher level. Among them, Cu­(DNAF)­(H 2 O) 3 possesses the highest oxygen balance of 10.5%, indicating comparatively complete energy release during the decomposition process.…”