A Pair of Multifunctional Cu(II)–Dy(III) Enantiomers with Zero–Field Single–Molecule Magnet Behaviors, Proton Conduction Properties and Magneto–Optical Faraday Effects

Abstract

Multifunctional materials with a coexistence of proton conduction properties, single–molecule magnet (SMM) behaviors and magneto–optical Faraday effects have rarely been reported. Herein, a new pair of Cu(II)–Dy(III) enantiomers, [DyCu2(RR/SS–H2L)2(H2O)4(NO3)2]·(NO3)·(H2O) (R–1 and S–1) (H4L = [RR/SS] –N,N′–bis [3–hydroxysalicylidene] –1,2–cyclohexanediamine), has been designed and prepared using homochiral Schiff–base ligands. R–1 and S–1 contain linear Cu(II)–Dy(III)–Cu(II) trinuclear units and possess 1D stacking channels within their supramolecular networks. R–1 and S–1 display chiral optical activity and strong magneto–optical Faraday effects. Moreover, R–1 shows a zero–field SMM behavior. In addition, R–1 demonstrates humidity– and temperature–dependent proton conductivity with optimal values of 1.34 × 10−4 S·cm−1 under 50 °C and 98% relative humidity (RH), which is related to a 1D extended H–bonded chain constructed by water molecules, nitrate and phenol groups of the RR–H2L ligand.