A Series of (6,6)-Connected Porous Lanthanide Organic Framework Enantiomers with High Thermostability and Exposed Metal Sites: Scalable Syntheses, Structures, and Sorption Properties

A series of microporous lanthanide-organic framework enantiomers, Ln(BTC)(H2O) . (DMF)(1.1) (Ln = Y 1a, 1b; Tb 2a, 2b; Dy 3a, 3b; Er 4a, 4b; Yb 5a, 5b, BTC = 1,3,5-benzenetricarboxylate; DMF = N,N-dimethylformamide) with unprecedented (6,6)-connected topology have been prepared and characterized. All these compounds exhibit very high thermal stability of over 450 degrees C. The pore characteristics and gas sorption properties of these compounds were investigated at cryogenic temperatures by experimentally measuring nitrogen, argon, and hydrogen adsorption/desorption isotherms. The studies show that all these compounds are highly porous with surface areas of 1080 (1), 786 (2), 757 (3), 676 (4), and 774 m(2)/g (5). The amounts of the hydrogen uptakes, 1.79 (1), 1.45 (2), 1.40 (3), 1.51 (4), and 1.41 wt % (5) at 77 K (1 atm), show their promising H-2 storage performances. These porous materials with considerable surface areas, high voids of 44.5% (1), 44.8% (2), 47.7% (3), 44.2% (4), and 45.7% (5), free windows of 6-7 angstrom, available exposed metal sites and very high thermal stability can be easily prepared on a large scale, which make them excellent candidates in many functional applications, such as, gas storage, catalysis, and so on.