A simple but efficient strategy to enhance hydrostability of intensely fluorescent Mg-based coordination polymer (CP) via forming a composite of CP with hydrophobic PVDF

Abstract

A coordination polymer (CP) of Mg²⁺ with 1,3,5-benzenetricarboxylate (BTC³⁻) was synthesized using a solvothermal method. The Mg-CP, with a formula of Mg₃(BTC)(HCOO)₃(DMF)₃, crystallizes in the trigonal space group P, with cell parameters of a = b = 13.972(5) Å, c = 8.090(5) Å and V = 1367.6(11) ų, and shows a lamella structure built from planar rosette-type hexanuclear architectures. The Mg-CP emits intense blue fluorescence arising from π* → π transition of intra-ligand of BTC³⁻ with 21.69% quantum yield, yet it exhibits poor stability to water. The composites of Mg-CP with hydrophobic polyvinylidene fluoride (PVDF) were sequentially prepared by mechanically mixed, tableted and annealed processes, which showed good compatibility between Mg-CP and PVDF, high hydrostability, and intense blue emission. This study suggests a simple but efficient method to solve the drawbacks of some functional CPs unstable to water and to promote them as practical applications in the field of functional materials.