Supramolecular Assembly of Chiral Lanthanide Triple-Decker Metallocyclophanes Ln ₃ ( <b>L</b> ^<b>meta</b> ) ₃ (L ^{<i>R</i> / <i>S</i>} ) ₃ or Tetrahedral Cages Ln ₄ ( <b>L</b> <sup>

Two new ligands (<b>L</b>^<b>meta</b>: <i>meta</i>-tris-β-diketonate and <b>L</b>^<b>para</b>: <i>para</i>-tris-β-diketonate) with meta and para orientations of coordinating bidentate β-diketonate units were synthesized in order to investigate their supramolecular formation behavior. When chiral (<i>R</i>)- or (<i>S</i>)-BINAPO (L^{<i>R</i>/<i>S</i>}) was used as a chiral inducer, trinuclear triple-decker metallocyclophane, Eu₃(<b>L</b>^<b>meta</b>)₃(L^{<i>R</i>/<i>S</i>})₃, was formed from <b>L</b>^<b>meta,</b> whereas a tetranuclear tetrahedral cage Eu₄(<b>L</b>^<b>para</b>)₄(L^{<i>R</i>/<i>S</i>})₄ was formed with <b>L</b>^<b>para</b>. The X-ray crystal of Eu₃(<b>L</b>^<b>meta</b>)₃(L^<i>S</i>)₃ shows that all three Eu centers possess the same configuration, hence resulting in homochiral ΔΔΔ assembly. The triple-decker exhibited a longer luminescence lifetime (∼0.98 ms vs ∼0.74 ms) and higher quantum yields (∼66% vs ∼50%) than the tetrahedral cage. Moreover, chiroptical properties were observed for a lanthanide triple-decker metallocyclophane: Mirror-image circular dichroism of chiral Eu₃(<b>L</b>^<b>meta</b>)₃(L^{<i>R</i>/<i>S</i>})₃ or Eu₄(<b>L</b>^<b>para</b>)₄(L^{<i>R</i>/<i>S</i>})₄ discloses their enantiomeric behavior and chiral transmission from (<i>R</i>)- or (<i>S</i>)-BINAPO moiety to achiral <b>L</b>^<b>meta</b> and <b>L</b>^<b>para</b>. Furthermore, their circularly polarized luminescence indicated that the |<i>g</i>_lum| can reach 0.13 for the triple-decker metallocyclophane and 0.16 for the tetrahedral cage.