Dysprosium(III) Metal-Organic Framework Demonstrating Ratiometric Luminescent Detection of pH, Magnetism, and Proton Conduction.

A multifunctional metal-organic framework, (Hdmbpy)[Dy(Hdobdc)(HO)]·3HO (, Hdobdc = 2,5-dihydroxyterephthalic acid, dmbpy = 4,4'-dimethyl-2,2'-bipyridine), was synthesized and structurally characterized. The metal center Dy is connected by four carboxyl groups to form the [Dy(CO)] binuclear nodes, which are further interconnected by eight separate Hdobdc ligands to form a three-dimensional (3D) framework including hydrophilic triangular channels and abundant hydrogen-bonding networks. has good stability in aqueous solution as well as in harsh acidic or alkaline solutions (pH range: 2.0-12.0). Furthermore, the luminescence signal of undergoes a visualized color change as the acidity of the solution alters, which is the typical behavior of pH ratiometric probe. At a 100% relative humidity, exhibits a high proton conductivity σ (1.70 × 10 S cm at 303 K; 1.20 × 10 S cm at 343 K) based on the proton hopping mechanism, which can be classified as a superionic conductor with σ exceeding 10 S cm. Additionally, the ferromagnetic interaction and magnetic relaxation behavior are simultaneously achieved in . Herein, the combination of luminescence sensing, magnetism, and proton conduction in a single-phase 3D MOF may offer great potential applications in smart multitasking devices.