A 3D homochiral metal-organic framework with high selective adsorption property

A novel homochiral three-dimensional coordination compound, namely [Eu-3(H(6)Q(3)Cl(4)(NO3)(5)center dot 39H(2)O](n) (1, containing an equal amount of enantiomers) (H6L = cryptand hexacarboxylic acid, see Fig. S1) has been synthesized by the achiral precursor (H6L) via spontaneous resolution. Single-crystal X-ray diffraction analysis of 1 indicates that the compound possesses 1D chiral open channels formed by triple-stranded helical chains, with solvent accessible volume of 23.8%. The crystals of 1 are optically active and opposite Cotton effects can be observed in the circular dichroism (CD) spectra. Compound I can selectively adsorb water over organic solvents (MeOH, EtOH, MeCN, THF) and exhibit reversible water adsorption upon dehydration and hydration, which was indicated by the powder X-ray diffraction, infrared spectra, thermogravitric and elemental analyses.