In Situ Coordination-Catalyzed <i>o</i>-Vanillin Underwent a One-Pot Tandem Reaction to Construct Complex Chiral Tetrameric Isomer-Based Hexanuclear Clusters

In this work, Dy(NO₃)₃·6H₂O and <i>o</i>-vanillin reacted under "one-pot" conditions, achieving for the first time four efficient condensations of <i>o</i>-vanillin and obtaining a pair of chiral hexanuclear clusters <i>R</i>/<i>S</i>-<b>Dy</b>_<b>6</b>. The four Dy(III) ions in the structure of <i>R</i>/<i>S</i>-<b>Dy</b>_<b>6</b> are arranged in a planar quadrilateral with a Dy(III) ion derived from each of the upper and lower ends, forming a shape similar to a "chair". The complex chiral ligands H₄L_R¹ and H₄L_S¹ were obtained from simple <i>o</i>-vanillin through a multistep tandem reaction. Their formation process involved a series of reaction steps, including a free radical coupling reaction to form pinacol and an in situ tandem reaction of pinacol and <i>o</i>-vanillin. Magnetic studies show that the Dy(III) ions in <i>R</i>/<i>S</i>-<b>Dy</b>_<b>6</b> have magnetic anisotropy and/or low excited states. In addition, <i>R</i>/<i>S</i>-<b>Dy</b>_<b>6</b> has an outstanding ability to produce reactive oxygen species under low-power light irradiation and shows excellent photodynamic sterilization. The inhibition zones against <i>Escherichia coli</i> are about 2.09 and 2.99 cm, and the inhibition zones against <i>Staphylococcus aureus</i> are about 2.51 and 2.93 cm, respectively. This work not only provides a vivid example for the synthesis of complex chiral organic products but also promotes the progress of lanthanide clusters' crystal engineering.