A series of transition metal coordination polymers with mixed ligands: Specific sensing and removal of metal ions

Abstract

Starting from the transition metal salts and mixed organic ligands of 4,4′-{[1,2-phenylenebis-(methylene)]bis(oxy)}dibenzoic acid (H2L) and different N-containing linkers, six new coordination polymers, [Cd(L)(2,2′-bipy)]n (1); [Cu(L)(2,2′-bipy)]n (2); {[Zn(L)(4,4′-bipy)][Zn(L)(H2O)]}n (3); [Cu(L)(4,4′-bipy)0.5 (H2O)]n (4), [Zn2(L)2(bpp)]n (5) and [Cd3(L)2(OAc)2(Him)2]n (6) (2,2′-bipy=2,2′-bipyridine, 4,4′-bpy=4,4′-bipyridine and bpp=1,3-bis(4-pyridyl)propane), were synthesized and characterized. The structural differences of 1–6 indicate the effect of the auxiliary N-donor ligands and nature of metal centers could modulate the resulting architectures. The photoluminescent sensing behaviours of 1 and 5 toward Cu2+ cation and nitro explosives have been investigated in detail. Interestingly, the immobilized Cu2+ cation can be easily separated by ethylenediaminetetraacetic acid (EDTA).