Two fluorescent copper phosphonate complexes for sensing antibiotics, ketones and Fe3+ in water

Abstract As the most attractive and fastest growing fluorescent sensing materials, metal‐organic compounds have demonstrated great potential for the detection of various types of chemicals. Two fluorescent phosphonate complexes [Cu 3 O 2 (HL) 2 ⋅ 2H 2 O] (1) and [Cu(H 2 L) 2 ⋅ 3H 2 O] (2) with diverse structures were designed and synthesized for this purpose from ((2’‐cyano‐[1,1’‐biphenyl]‐4‐yl)methyl)phosphonic acid (H 2 L) and copper ions with various valence state under solvothermal conditions. The structures of 1 and 2 are determined by single X‐ray crystal diffraction, and further characterized by elemental analysis, IR, TGA and PXRD. The two complexes demonstrate diverse properties on sensing Fe 3+ ions, ketone and some antibiotics, and the according detection limits are obtained, indicating which could be applied as a fast, recyclable, and multi‐responsive fluorescence sensor. The sensing activity diversity between 1 and 2 toward different analytes was also discussed based on the possible sensing mechanisms to further explore the possible factors affecting the sensibility of the materials.