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2,9,9,10,10-Pentanitro-2-azaadamantane-4,8-diyl dinitrate, the first member of the heptanitroazaadamantane family, was synthesized by a two-shell arrangement strategy for nitro group introduction.

An unusual protocol of a “one-pot” three-step strategy to build the 2,4,6,8-tetraazaadamantane skeleton was developed. 17 products were obtained in 19–46% yields, and the N-benzyl groups were transferred to nitroso, acetyl, benzoyl and nitro groups.

A 2D sql framework and an unprecedented binodal 5,6-connected 3D net have been constructed from Mn(ii) ions and two tetrazole-based carboxylic acids.

The past decades have witnessed the feat of fluorescent probes for Fe3+ detection, where eliminating the interference by other metal ions plays a pivotal role in its detection by probes in complex environments.

Nitrogen-rich heterocyclic compounds (NRHCs) are an emerging type of explosive, and their quantification is important in national security inspection and environmental monitoring. Up until now, designing an efficient NRHCs sensing strategy was still in the early stages. Herein, a new metal-organic framework (MOF) with aggregation-induced emission (AIE) characteristics is synthesized with fluorometric/colorimetric responses for rapid and selective detection of NRHCs. The nonemissive probe is designed with tetraphenylethylene derivative as the linker and Co as the node, quencher, and color-changing agent. Cobalt AIE-MOF exhibits a turn-on emission enhancement due to the competitive coordination substitution between NRHCs and the scaffold as well as the following AIE process of the liberative linkers. Meanwhile, the color appearance of the probe changes from blue to yellow based on the dissociation of the original Co coordinating system. Using this dual-mode probe, single- and dual-ring NRHCs are successfully detected from 5 μM to 7.5 mM within 25 s. The cobalt AIE-MOF exhibits excellent selectivity of NRHCs against a variety of interferences, providing a promising tool for designing a multichannel detection strategy.

The design and synthesis of metal–organic frameworks (MOFs) have attracted much interest due to the intriguing diversity of their architectures and topologies. However, building MOFs with different topological structures from the same ligand is still a challenge. Using 3-nitro-4-(pyridin-4-yl)benzoic acid (HL) as a new ligand, three novel MOFs, namely poly[[(N,N-dimethylformamide-κO)bis[μ2-3-nitro-4-(pyridin-4-yl)benzoato-κ3 O,O′:N]cadmium(II)] N,N-dimethylformamide monosolvate methanol monosolvate], {[Cd(C12H7N2O4)2(C3H7NO)]·C3H7NO·CH3OH} n , (1), poly[[(μ2-acetato-κ2 O:O′)[μ3-3-nitro-4-(pyridin-4-yl)benzoato-κ3 O:O′:N]bis[μ3-3-nitro-4-(pyridin-4-yl)benzoato-κ4 O,O′:O′:N]dicadmium(II)] N,N-dimethylacetamide disolvate monohydrate], {[Cd2(C12H7N2O4)3(CH3CO2)]·2C4H9NO·H2O} n , (2), and catena-poly[[[diaquanickel(II)]-bis[μ2-3-nitro-4-(pyridin-4-yl)benzoato-κ2 O:N]] N,N-dimethylacetamide disolvate], {[Ni(C12H7N2O4)2(H2O)2]·2C4H9NO} n , (3), have been prepared. Single-crystal structure analysis shows that the CdII atom in MOF (1) has a distorted pentagonal bipyramidal [CdN2O5] coordination geometry. The [CdN2O5] units as 4-connected nodes are interconnected by L − ligands to form a fourfold interpenetrating three-dimensional (3D) framework with a dia topology. In MOF (2), there are two crystallographically different CdII ions showing a distorted pentagonal bipyramidal [CdNO6] and a distorted octahedral [CdN2O4] coordination geometry, respectively. Two CdII ions are connected by three carboxylate groups to form a binuclear [Cd2(COO)3] cluster. Each binuclear cluster as a 6-connected node is further linked by acetate groups and L − ligands to produce a non-interpenetrating 3D framework with a pcu topology. MOF (3) contains two crystallographically distinct NiII ions on special positions. Each NiII ion adopts an elongated octahedral [NiN2O4] geometry. Each NiII ion as a 4-connected node is linked by L − ligands to generate a two-dimensional network with an sql topology, which is further stabilized by two types of intermolecular OW—HW...O hydrogen bonds to form a 3D supramolecular framework. MOFs (1)–(3) were also characterized by powder X-ray diffraction, IR spectroscopy and thermogravimetic analysis. Furthermore, the solid-state photoluminescence of HL and MOFs (1) and (2) have been investigated. The photoluminescence of MOFs (1) and (2) are enhanced and red-shifted with respect to free HL. The gas adsorption investigation of MOF (2) indicates a good separation selectivity (71) of CO2/N2 at 273 K (i.e. the amount of CO2 adsorption is 71 times higher than N2 at the same pressure).

Polynitroazaadamantanes have a broad application prospect in the field of energetic materials. Herein, the synthesis of 2,4,4,8,8-pentanitro-2-azaadamantane, a new member of polynitroazaadamantane family, is described in detail. It was prepared with 11 steps in an overall yield of 8.8% starting from easily accessible compounds. It has high thermal stability and high density.

Three luminescent Pt(II) complexes, [Pt(5-NO2-ppy)(H-5-NO2-ppy)(Cl)] (1), [Pt(2-(2′,4′-dF)-ppy)(H-2-(2′,4′-dF)-ppy)(Cl)] (2), [Pt(2-(3′,5′-dF)-ppy)(H-2-(3′,5′-dF)-ppy)(Cl)] (3) with 2-phenyl-5-nitropyridyl (5-NO2-ppy), 2-(2,4-difluorophenyl)pyridine (2-(2′,4′-dF)-ppy) and 2-(3,5-difluorophenyl)pyridine(2-(3′,5′-dF)-ppy) were synthesized. FT-IR spectroscopy, multinuclear NMR spectroscopy and single-crystal X-ray crystallography were used to determine their structures. The UV–vis absorption and photoluminescence (PL) spectra of 1–3 were measured. 1–3 displayed rich photophysical properties with the maximum emission wavelengths in the range of 403 to 527 nm in the photoluminescence spectra, which demonstrated 1–3 have the potential to become the DNA luminescent probes in living cells. The anticancer activities of these complexes were tested in vitro by MTT assay against four tumor cell lines BGC823, MGC803 (human gastric cancer cell lines), HepG2 (human hepatocellular carcinoma), A549 (human non-small-cell lung cancer cell lines), HL-7702(human normal liver cell line). Moreover, 3 displayed highest cytotoxicity against human gastric cancer cell lines with the values of IC50 in the range of 13.036–26.594 μM.

When the scale of biomass straw energy utilization project is relatively large, it is necessary to build a biomass straw storage and logistics center to ensure the stability of the project. By biomass straw lowest total logistics cost as the objective, considering the biomass straw briquette processing, variable cost and fixed cost of biomass straw storage cost and biomass straw warehousing logistics center construction cost to build the mixed integer programming model, to determine the biomass straw warehousing logistics center location, flow rate and maximum capacity. Taking Henan Province as an example, the paper selects the stalk storage and logistics center of biomass straw in Xinyang Jinniu Logistics Industry concentration area, Nanyang River logistics park and Zhoukou Port comprehensive logistics park through model calculation.

The gas pipelines usually undergo complicated and changeable regional environment. As the level of the potential difference or pipeline’s route changes in the space and therefore elastic bending cannot meet the needs when pipe changes its direction, we generally use pipe bend to connect two pipelines with different spatial extend direction during the pipe laying period, and it can reduce the temperature stress. Unreasonable design of elbow will lead to pipeline damage. We established mountain area pipeline model, and conducted analysis on pipeline stress under different elbow angles. Research shows that different angles of the bends suffer different operation stress, and we have come to the conclusion that the angle of pipe bends should not be within the range of 15 degrees to 35 degrees.

This research aims to develop an analytical approach to study the heat transfer problem of thermal protection systems (TPS) for hypersonic vehicles. Laplace transform and integral method are used to describe the temperature distribution through the TPS subject to aerodynamic heating during flight. Time-dependent incident heat flux is also taken into account. Two different cases with heat flux and radiation boundary conditions are studied and discussed. The results are compared with those obtained by finite element analyses and show a good agreement. Although temperature profiles of such problems can be readily accessed via numerical simulations, analytical solutions give a greater insight into the physical essence of the heat transfer problem. Furthermore, with the analytical approach, rapid thermal analyses and even thermal optimization can be achieved during the preliminary TPS design.

A novel diol-functionalized poly(ethylene glycol)-bridged dicationic ionic liquid ([diol-PEG1000-DIL][PF6]) is prepared and used as an efficient and reusable ligand for copper-catalyzed amination. A variety of aryl iodides and aryl bromides reacted smoothly with aqueous ammonia to afford the corresponding aromatic primary amines in good to excellent yields. It is remarkable that aryl chlorides with a strong electron-withdrawing group exhibited a dramatically elevated activity in the presence of tetrabutylammonium bromide. Furthermore, the catalyst could be easily recovered and reused without obvious loss of catalytic activity after five recycling runs.

A novel diol-functionalized poly(ethylene glycol)-bridged dicationic ionic liquid ([diol-PEG1000-DIL][PF6]) is prepared and used as an efficient and reusable ligand for copper-catalyzed amination. A variety of aryl iodides and aryl bromides reacted smoothly with aqueous ammonia to afford the corresponding aromatic primary amines in good to excellent yields. It is remarkable that aryl chlorides with a strong electron-withdrawing group exhibited a dramatically elevated activity in the presence of tetrabutylammonium bromide. Furthermore, the catalyst could be easily recovered and reused without obvious loss of catalytic activity after five recycling runs.