Chiral Nanoparticle-Induced Enantioselective Amplification of Molecular Optical Activity
Leung, Ken Cham-Fai
KAUST DepartmentAdvanced Membranes and Porous Materials Research Center
Chemical Science Program
Nanostructured Functional Materials (NFM) laboratory
Physical Science and Engineering (PSE) Division
Permanent link to this recordhttp://hdl.handle.net/10754/630682
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AbstractEnantiodifferentiation is of fundamental importance in chiral chemistry and substantially requires high optical activity (OA) of enantiomers; but the enantiomeric OA is typically weak due to subwavelength molecular dimension, leading to a lack of sensitive enantiodifferentiation. A new approach is devised to evidently amplify the enantiomeric OA by anchoring axially chiral molecules containing the binaphthyl chromophore on silver chiral nanoparticles (AgCNPs) with a sub-5 nm helical pitch (P). Compared to the OA of dissolved enantiomers, that of (R)- and (S)- enantiomers can be enantioselectively amplified on right-handed and left-handed AgCNPs, respectively, in as high as one order of magnitude. The enantioselective amplification is probably ascribed to the enantiospecific adsorption-induced change in the dihedral angle of the binaphthyl chromophore, resulting from chirality transfer from chiral footprints of the AgCNPs to the binaphthyl chromophore through the Ag–S bicontacts. The enantioselective amplification tends not to occur as long as P > 5 nm or on achiral Ag nanoparticles, due to a lack of the chirality transfer. This work imposes the significant application of enantiodifferentiation, which is on practical demand for producing single-enantiomer pharmaceutics and pesticides with no fatal adverse effect, on the emerging chiral metamaterials composed of metallic CNPs.
CitationYang L, Kwan C, Zhang L, Li X, Han Y, et al. (2018) Chiral Nanoparticle-Induced Enantioselective Amplification of Molecular Optical Activity. Advanced Functional Materials: 1807307. Available: http://dx.doi.org/10.1002/adfm.201807307.
SponsorsThe authors thank Winnie Wu (IAM, HKBU) for technical support with XPS. This work was financially supported by NSFC/21473149, SKLP-1718-P03 (HKBU), and HKBU8/CRF/11E (GLAD).
JournalAdvanced Functional Materials