Reversible Anion Exchanges of Porous Metal−Organic Frameworks: Syntheses and Structures of Silver Complexes with Novel Rigid Tripodal Nitrogen Ligands

Abstract

Two novel new rigid tripodal arene core based nitrogen ligands, 1,3,5-tris(pyrazol-1-yl) benzene (L1) and 1,3,5-tris[p-(pyrazol-1-yl)phenyl]benzene (L2), have been synthesized. Self-assembly of L1 with silver(I) salts generated two three-dimensional porous supramolecular networks, {[Ag3L12X2]X}n (1, X = ClO4-; 2, X = NO3-), with a common (10,3)-a topology. L2 reacts with silver nitrate, resulting in a one-dimensional chain which constructs a three-dimensional supramolecular network, {[Ag4L22(NO3)4]·2CH3OH}n(3), via hydrogen bonds. Three complexes have been structurally characterized. The anion exchanges were determined by IR spectroscopy, elemental analyses, and X-ray powder diffraction for complexes 1 and 2; the counteranions located in the cationic frameworks can be exchanged reversibly without destruction of the structures. This observation demonstrates that 1 and 2 can act as zeolite-like porous materials for anion exchange. The photoluminescent properties of 1,3,5-tris[p-(pyrazol-1-yl)phenyl]benzene ...