The demand for xylenes is projected to increase over the coming decades. The separation of xylene isomers, particularly pand m-xylenes, is vital for the production of numerous polymers and materials. However, current state-of-the-art separation is based upon fractional crystallisation at 220 K which is highly energy intensive. Here, we report the discrimination of xylene isomers via refinement of the pore size in a series of porous metal-organic frameworks, MFM-300, at sub-angstrom precision leading to the optimal kinetic separation of all three xylene isomers at room temperature. The exceptional performance of MFM-300 for xylene separation is confirmed by dynamic ternary breakthrough experiments. In-depth structural and vibrational investigations using synchrotron X-ray diffraction and terahertz spectroscopy define the underlying host-guest interactions that give rise to the observed selectivity (p-xylene < o-xylene < m-xylene) and separation factors of 4.6-18 for pand mxylenes.

Two new three-dimensional isostructural lanthanide metal-organic frameworks (Ln(III)-MOFs), [LnL(HO)]·3HO·0.75DMF (1-Ln; Ln = Dy(III) and Eu(III) ions, HL = biphenyl-3'-nitro-3,4',5-tricarboxylic acid, DMF = N,N'-dimethylformamide), were synthesized and characterized. The appearance of temperature-dependent out-of-phase (χ″) signal reveals that complex 1-Dy displays slow magnetic relaxation behavior with the energy barrier (ΔU) of 57 K and a pre-exponential factor (τ) of 3.89 × 10 s at 1200 Oe direct current field. The luminescence explorations demonstrated that 1-Eu exhibits high quenching efficiency and low detection limit for sensing nitrobenzene and CrO. Meanwhile, the fluorescence intensity of the quenched 1-Eu samples will be resumed after washing with DMF or water, indicating that 1-Eu may be used as a highly selective and recyclable luminescence sensing material for sensing nitrobenzene and CrO anion.

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Five coordination polymers with different dimensional structures have been solvothermally synthesized by utilizing H2dtp ligand. Complexes1and2reveal strong solid-state luminescence, and complexes3–5display antiferromagnetic exchange.