Multifunctional Dinuclear Dy-Based Coordination Complex Showing Visible Photoluminescence, Single-Molecule Magnet Behavior, and Proton Conduction.

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 single-molecule 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.