A Robust Strontium Coordination Polymer with Selective and Sensitive Fluorescence Sensing Ability for Fe(3+) Ions

Exploration of sensitive and selective fluorescence sensors towards toxic metal species is of great importance to solve metal pollution issues. In this work, a three-dimensional (3D) strontium coordination polymer of Sr(2)(tcbpe) (H(4)tcbpe = 1,1,2,2-tetrakis(4-(4-carboxy-phenyl)phenyl)ethene) has been synthesized and developed as a fluorescent sensor to Fe(3+) ions. Sr(2)(tcbpe) shows a mechanochromic fluorescence with emission shifting from blue of the pristine to green after being ground. Notably, based on a fluorescence quenching mechanism, Sr(2)(tcbpe) displays a sensitive and selective fluorescent sensing behavior to Fe(3+) ions with a detection limit of 0.14 mM. Moreover, Sr(2)(tcbpe) exhibits high tolerance to water in a wide pH range (pH = 3–13), demonstrating that Sr(2)(tcbpe) is a potential fluorescent sensor of Fe(3+) in water.