Two alkaline earth metal coordination polymers based on a new oxamate-dicarboxylate ligand: Selective fluorescence sensing of Fe3+ in aqueous solution

摘要

Two different alkaline earth metal coordination polymers (AE-CPs) {[Ca3L2(H2O)(6)]center dot 2H(2)O}(n) (1) and [Sr(H2L)(2)](n) (2) were constructed from using 5-(ethyl oxamate)-isophthalic acid (H2EtL) ligand with alkaline earth metal ions Ca2+ and Sr2+ under solvothermal conditions, respectively. Among them, L and H2L are formed by in-situ hydrolysis of H2EtL, which display multiple kinds of coordinated modes through oxamate and carboxylate groups. 1 and 2 both show three-dimensional coordination frameworks possessing unprecedented (3,4,5)-connected skgl topology and (3,6)-connected ant topology, respectively. The solid-state fluorescence properties of 1 and 2 were studied, and 1 with bright blue luminescence reveals selective sensing toward Fe3+ ion in water with the low detection limit (LOD) of 1.04 x 10(-3) M.