Microporous 3-D chiral metal-organic framework with a quartzlike topology based on an achiral building unit

Abstract

A zinc coordination polymer, Zn(IN)2 · 2H2O (1) (HIN = isonicotinic acid), has been synthesized and characterized by IR, elemental analysis, thermogravimetric analysis, and single crystal X-ray diffraction. This compound crystallizes in the chiral space group P62 with a = 15.512(3), b = 15.512(3), c = 6.262(2) Å, V = 1304.9(5) Å3, and Z = 3. The O and N atoms of the IN ligand are coordinated to a ZnII ion, locking the asymmetry of the IN ligand and transferring this asymmetry throughout the crystal structure to “direct” the formation of a chiral network. The structure of 1 is characteristic of a 3-D quartz-like framework, which contains hetero-chiral helical channels (pseudo-trigonal and hexagon channels) alternately along the c-axis. Compound 1 exhibits high stability and intense fluorescent emission at room temperature.