Combined performance of circularly polarized luminescence and proton conduction in homochiral cadmium(ii)–terbium(iii) complexes

Abstract

Multifunctional materials with proton conduction, circularly polarized luminescence (CPL) and a magneto-optical Faraday effect would provide a great opportunity for applications in luminescent, electrical, magneto-optical and optical–electronic smart devices. However, such types of multifunctional systems have rarely been reported. Herein, by introducing a chiral amine–phenol ligand, a pair of Cd(II)–Tb(III) enantiomers, [Cd₂Tb(RR/SS-H₂L)₂(H₂O)₆](ClO₄)₃·2H₂O (R-1 and S-1) [H₂L = ((SS/RR)-cyclohexane-1,2-diylbis(azanediyl)-bis(methylene)-bis(2-methoxyphenol))], were obtained. R-1 and S-1 feature the homochiral molecules of trinuclear Cd₂Tb structures, which contain abundant H-bonds to form three-dimensional (3D) supermolecular frameworks. They are chiral multifunctional materials showing strong Tb(III) characteristic emissions, a moderate proton conductivity of 1.17 × 10⁻⁴ S cm⁻¹ at 333 K and 100% RH for R-1, CPL with a luminescence dissymmetry factor value of over 10⁻³ for R-1 and S-1 and a strong magneto-optical Faraday effect, and they are the first known materials simultaneously showing CPL, proton conduction and the Faraday effect.