Zinc(II) coordination polymers with substituted benzenedicarboxylate and tripodal imidazole ligands: syntheses, structures and properties

By introducing 1,4-benzenedicarboxylic acid (H2BDC) with different substituent groups H2BDC-R (R = NH2, OH, NO2) into the Zn(II)-1,3,5-tris(1-imidazolyl) benzene (tib) system, four new zinc(II) coordination polymers, namely [Zn-5(tib)(2)(BDC-NH2)(4)(2-OH)(2)]center dot H2O (1), [Zn-2(tib)(BDC-NH2)SO4(H2O)(2)]center dot 5H(2)O (2), [Zn-2(tib)(2)(HBDC-OH)(2)(BDC-OH)]center dot 2H(2)O (3) and [Zn(tib)(BDC-NO2)]center dot H2O (4), have been successfully synthesized under solvothermal conditions. Complexes 1 and 2 based on the same H2BDC-NH2 show different structures: 1 is a 3-fold interpenetrated 3D framework with point (Schlafli) symbol {5(3).6(2).7}(2){5(3)}(2){5(8).6(2).8(5)}, while 2 exhibits a 2D network with {6(2).8(4)}{6(2).8}(4) topology. 3 and 4 are 2D networks with different topologies of {6(3)} and {4(4).6(2)}, respectively. The structural diversity of 1-4 indicates that the substituent groups of H2BDC as well as the reaction temperature and solvent play an important role in determining the framework structures and topologies. Furthermore, the sorption and photoluminescence properties of the complexes were investigated.