Chiral Inversion and Conservation of Clusters: A Case Study of Racemic Ag<sub>32</sub>Cu<sub>12</sub> Nanocluster
Jinsong Chai, Sha Yang, Tao Chen, Qinzhen Li, Shuxin Wang, Manzhou Zhu
Abstract
Chiral metal nanoclusters have been widely reported, but their separation and optical stabilization remain challenging. We used a deracemization strategy to accomplish the enantioseparation of a racemic mixture of [Ag32Cu12(CH3COO)12(SAdm)12(P(CH3OPh)3)4] (M44) in a yield exceeding 50%, forming two optically active [Ag32Cu12(R/S-Cl(CH3)CHCOO)12(SAdm)12(P(CH3OPh)3)4] (R/S-M44′) enantiomers. The optical activity of these products was conserved after exchange of the chiral carboxyl ligands with achiral ligand (Br–), to give two additional optically active nanoclusters R/S-[Ag28Cu16Br12(SAdm)12(P(CH3OPh)3)4] (R/S(Br)-M44). The crystal structures of the above nanoclusters were determined by single-crystal X-ray crystallography. Based on these structures, the chiral transformation and conservation are mapped out.