Solvent-dependent zinc(II) coordination polymers with mixed ligands: selective sorption and fluorescence sensing

Starting from the same metal salts and mixed organic ligands of 1,3,5-tris(1-imidazolyl)benzene (tib) and 2-bromo-1,4-benzenedicarboxylic acid (H2BDC-Br), two novel zinc(II) coordination polymers [Zn-2(tib)(2)(BDC-Br)](2)center dot 2SO(4)center dot 17H(2)O (1) and [Zn-4(tib)(2)(BDC-Br)(3)(H2O)(4)SO4]center dot 7.5H(2)O center dot 2.5DMF (2) (DMF = N,N-dimethylformamide) were obtained by using different solvent systems of DMF/H2O and DMF/EtOH/H2O, respectively. 1 is an unusual (3,4)-connected 3D net with a Point symbol of {4 center dot 8 center dot 10(4)}{4 center dot 8 center dot 10}, while 2 is a complicated 1D chain, which is further connected to form a 3D supramolecular architecture by hydrogen bonding interactions. In particular, 1 and 2 exhibit selective adsorption of CO2 over N-2 and show good selectivity for detection of acetone via fluorescence quenching.