Synthesis, crystal structure, chiroptical and ferroelectric properties of a multifunctional chiral silver(I) complex based on the chiral bis-bidentate bridging ligand

Abstract

Using a chiral bis-bidentate isomer (–)-2,5-bis(4,5-pinene-2-pyridyl)pyrazine (LR) as bridging ligand to react with AgNO3 under solvothermal conditions, a chiral silver(I) complex formulated as [Ag(LR)·NO3]n (1) was obtained. Single crystal X-ray analysis revealed that 1 crystallizes in the non-centrosymmetric space group C2 with an infinite one-dimensional (1D) zigzag chain structure which is further linked together by C–H⋯π interactions to form a three-dimensional (3D) supramolecular framework. Each four-coordination Ag(I) atom is ligated by four N atoms from two LR ligands forming a distorted tetrahedral geometry. Circular dichroic (CD) spectrum confirmed its chiroptical activity. The measurements of second harmonic generation (SHG) and ferroelectric behavior showed that 1 displays nonlinear optical (NLO) activity and ferroelectricity. Furthermore, the investigation on luminescence property showed that 1 exhibits ligand center emission. All these indicate that 1 presents potential molecular-based multifunctional materials.