| Chiral lanthanide helical architectures have received intense attentions in recent years because of their potential applications as chiral probes and sensors and as circularly polarized luminescence?CPL?materials.However,stereoselectivity control in the self-assembly of lanthanide helicate is challenging due to the poor stereochemical preference and variable coordination numbers of Ln?III?ions.Two new tris-?-diketones,tris[?4-?4,4,4-trifluoro-1,3-dioxobutyl?-benzamido?ethyl]amine?TTEA?and tris[?7-?4,4,4-trifluoro-1,3-dioxobutyl?fluorene-2-formylamino?ethyl]amine?TFEA?has been designed and prepared for the synthesis of two series of dinuclear lanthanide complexes[Ln?TTEA??CH3OH?2][Ln=Eu?1?,Gd?2?,Sm?3?,Nd?4?,Yb?5?,Ho?6?,Er?7?]and[Ln?TFEA??CH3OH?2][Ln=Eu?12?,Gd?13?,Sm?14?,Nd?15?,Yb?16?,Ho?17?,Er?18?].Complexes 1–7 and 12–18 have been characterized by various spectroscopic techniques and their photophysical properties are investigated.We reported the employing chiral ancillary ligand R/S-BINAPO to induce achiral tripodal ligand to form homochiral lanthanide triple-helical podates Ln?TTEA???R/S?-BINAPO?[Ln=Eu?R/S-8?,Gd?R/S-9?,La?R/S-10?,Yb?R/S-11?]and Ln?TFEA???R/S?-BINAPO?[Ln=Eu?R/S-19?,Gd?R/S-20?,La?R/S-21?,Yb?R/S-22?].X-ray crystallographic analysis for rac-8 reveals that the chirality of BINAPO is transferred during the self-assembly process to give either P or M helical architectures in podates.The 1H and 31P NMR and circular dichroism measurements confirm the diastereopurity of the assemblies in solution.A detailed optical and chiroptical characterization reveals that the luminescent enantiopure podates not only exhibit intense CPL with glum values but also show high luminescence quantum yields.Our results provide a feasible strategy for designing homochiral helical lanthanide supramolecular architecture and synthesizing excellent CPL materials. |
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