Luminescent metal−organic frameworks (MOFs) coupled with proton conduction offer wide applications in clean energy and luminescence sensors. High stability and remarkable proton conductivity and sensing are requisites for practical applications. Specifically, high thermal and chemical stabilities under harsh conditions are important but challenging to achieve. Herein, an ultra-stable Cu(I)-tetrazolate MOF, NaCu 3 (mtz) 4 (1, mtz = 5-methyltetrazolate), was prepared. It possesses a 3D framework with 1D channels and exhibits outstanding thermal and chemical stabilities under various conditions, including water, organic solvents, and acidic and basic solutions of wide pH range. The compound exhibits strong green emissions, which can be ascribed to metal-toligand charge transfer, and selective fluorescence sensing for pollutant nitrobenzene. Moreover, compound 1 presents a high proton conductivity of over 10 −2 S cm −1 at 70 °C and 100% relative humidity. In 1, abundant uncoordinated nitrogen atoms on the pore walls act as H-bonding acceptors to achieve its high proton conductivity under waterassisted conditions. The compound is an unprecedented water-dependent proton conductor of the tetrazole-based MOF, providing a new avenue to design robust and high-performance proton-conductive MOFs.

A new Dy-based complex, [Dy 2 (phen) 4 (PAA) 4 ]-(ClO 4 ) 2 (1), was obtained by using 4-hydroxyphenyl acetate (HPAA) as a ligand and 1,10-phenanthroline as an auxiliary ligand. Complex 1 shows a dinuclear structure and a 2D supramolecular layer constructed by π−π stacking interactions. The complex displays a characteristic Dy(III) emission. Moreover, magnetic susceptibility measurements revealed that 1 exhibits a singlemolecule magnet (SMM) behavior. In addition, it also shows a proton conductivity of 1.08 × 10 −5 S cm −1 under 353 K and 100% relative humidity conditions, which is mainly assigned to H-bonded networks formed by the undeprotonated and uncoordinated phenolic groups of HPAA ligands and guest water molecules. Remarkably, 1 is the first example of a dinuclear complex showing photoluminescence, SMM behavior, and proton conduction.