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An unprecedented 3D dynamic porous metal-organic framework assembled from fivefold interlocked closed nanotubes has been constructed, which exhibits highly selective adsorption of CO(2) over N(2) and H(2), as well as stepwise and hysteretic behaviors.

Mechanically Interlocked molecules, such as catenanes and rotaxanes, are of great interest due to their fascinating structures and potential applications, while such molecules have been mainly restricted to comprising components of interlocked rings or polygons. The constructions of infinite polycatenanes and polyrotaxanes by discrete cages remain great challenge, and only two infinite polycatenanes fabricated by discrete cages have been reported so far, while the structures of polyrotaxanes and polypseudo-rotaxanes fabricated by discrete build units have not been documented to date. Herein we report the first example of a two-dimensional (2D) polypseudo-rotaxane fabricated by stool-like build units, the second example of a one-dimensional (1D) polycatenane, and the second example of a three-dimensional (3D) polycatenane, which were assemblied by discrete tetrahedral cages. The pores of dehydrated 3D polycatenane are dynamic, and display size-dependent adsorption/desorption behaviors of alcohols.

A new three-dimensional metal-organic framework (MOF) sensor with molecular formula (C 2 H 6 NH 2 ) 2 [Tb 2 (ptptc) 2 (DMF)(H 2 O)]$DMF$6H 2 O (complex 1) has been constructed from terphenyl-3,3 0 ,5,5 0 -tetracarboxylic acid (H 4 ptptc) and terbium nitrate under solvothermal conditions. The structure of complex 1 was characterized by single-crystal X-ray diffraction analysis (XRD), elemental analysis, IR spectroscopy and thermogravimetric (TG) analysis, and the purity was further confirmed by powder X-ray diffraction (PXRD) analysis. XRD analysis reveals that complex 1 crystallizes in a triclinic system P 1 space group and consists of a three-dimensional anionic network which has one-dimensional channels. Fluorescence titration experiments showed that complex 1 displayed real-time, highly selective and sensitive fluorescence quenching behavior towards picric acid with a nanomolar scale experimental detection limit (100 nM). Recycling titration experiments suggested that the as-synthesized probe has good reversibility and can be used for at least five cycles in fluorescence titration experiments without obvious fluorescence intensity reduction or framework structure destruction. Furthermore, the high selectivity and sensitivity as well as good recyclability of complex 1 make it a potential fluorescent sensor for picric acid.

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A three-dimensional metal-organic framework (1) with fourfold interpenetrating diamondoid networks was constructed using a macrocyclic nickel(II) complex and a tetracarboxylic ligand 4,4',4″,4‴-(cyclohexane-1,2-diyibis(azanetriyl))tetrakis(methylene)tetrabenzoic acid as building blocks. Despite the fourfold interpenetration, 1 possesses one-dimensional channels that are occupied by water and CH3CN guest molecules. Once the guest molecules were removed, the framework and pores in desolvated 1 are dynamic with large adsorption hysteresis loops, which exhibit selective gas adsorption for CO2 at 195 K over N2 and H2 at 77 K and selective adsorption for methanol, ethanol, and n-propanol over isopropanol at 298 K.

Three new mixed-metal borates, K4Ba2[B14O20(OH)10]·3H2O (1), LiSr2[B10O16(OH)3] (2), and LiBa[B9O15] (3), have been made under hydro(solvo)thermal conditions and characterized by means of IR, UV-vis-near-IR, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction, respectively. 1 is a 1D chain constructed from B14O21(OH)10(10-) cluster units, 2 is of a 2D layer with nine-membered-ring windows built up of B10O19(OH)3(9-) cluster units, while 3 exhibits a 3D framework with 12-membered-ring channels composed of B3O7 cluster units.

A simple and efficient liquid chromatography-mass spectrometry (LC-MS) method was developed and validated for simultaneous quantitation of catalpol and harpagide in normal and diabetic rat plasma. Protein precipitation extraction with acetonitrile was carried out using salidroside as the internal standard (IS). The LC separation was performed on an Elite C18 column (150 × 4.6 mm, 5 µm) with the mobile phase consisting of acetonitrile and water within a runtime of 12.0 min. The analytes were detected without endogenous interference in the selected ion monitoring mode with positive electrospray ionization. Calibration curves offered satisfactory linearity (r > 0.99) at linear range of 0.05-50.0 µg/mL for catalpol and 0.025-5.0 µg/mL for harpagide with the lower limits of quantitation of 0.05 and 0.025 µg/mL, respectively. Intra- and inter-day precisions (RSD) were <9.4%, and accuracy (RE) was in the -6.6 to 4.9% range. The extraction efficiencies of catalpol, harpagide and IS were all >76.5% and the matrix effects of the analytes ranged from 86.5 to 106.0%. The method was successfully applied to the pharmacokinetic study of catalpol and harpagide after oral administration of Zeng-Ye-Decoction to normal and diabetic rats, respectively.