Hydrothermal Synthesis, Crystal Structure and Properties of 1D Zigzag Chain Zinc(II) Coordination Polymer Constructed from Nicotinic Acid and 1,4-Bis(imidazol-1-ylmethyl)benzene

Abstract

A zinc–nicotinate complex, {[Zn(na)2(µ-pbix)]∙H2O}n (1), was obtained from the reaction of zinc(II) acetate with nicotinic acid (Hna) and 1,4-bis(imidazol-1-ylmethyl)benzene (pbix) in water at 120 °C under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, single crystal and powder X-ray diffraction. The thermal stability and luminescent property for 1 were also reported. The asymmetric unit of 1 consists of one zinc(II) center, one pbix ligand, two na anions and one non-coordinated water molecule, giving a formula of {[Zn(na)2(µ-pbix)]∙H2O}n. The Zn(II) ion is coordinated by two nitrogen atoms from two different 1,4-bis(imidazol-1-ylmethyl)benzene ligands and two oxygen atoms from two different nicotinate (na) anions, thus showing a distorted tetrahedral geometry. The adjacent Zn(II) ions are linked into an infinite 1D zigzag chain by 1,4-bis(imidazol-1-ylmethyl)benzene ligands. Grand canonical Monte Carlo (GCMC) simulations were also performed to compute single-component H2 adsorption isotherms at a pressure range of 0.01–100 bar and at 298 K and 77 K. The maximum H2 uptake in 1 was found as 68 cm3/ g STP at 100 bar and 77 K. This study will be useful to accelerate the hydrothermal synthesis of new coordination polymers for gas storage applications.