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Updated: Jan 23, 2026
Light-driven Molecular Motors on Surfaces for Single Molecular Imaging
Published on: March 13, 2019
HPLC Chiral Separation and Elution Reversal Mechanism of a Typical Light-Driven Molecular Motor,
Wen-Long Zhang1, Xin-Yi Huang1, Can Xia1
1School of Chemistry, Key Laboratory of Process Control and Quality Evaluation of Chiral Drugs, Guangdong Provincial Drug Administration, Guangzhou Key Laboratory of Biomedical Analytical Chemistry, South China Normal University, Guangzhou, People's Republic of China.
Abstract:
1-(9H-Fluoren-9-ylidene)-2,3-dihydro-2-methyl-1H-benz[e]indene (short as FMB) as one of second-generation light-driven molecular motors contains a chiral carbon atom, and has attracted considerable attentions due to macroscopic chiral structures and light-driven behaviors through supramolecular assembly and cooperative effects. Herein, chiral analysis and semi-preparative separation of FMB enantiomers have been studied by high-performance liquid chromatography (HPLC) on polysaccharide-derived chiral stationary phases (CSPs). Effects of factors on chiral separation of FMB enantiomers, including type of CSP, composition and ratio of mobile phase, temperature, and flow rate, have been discussed in detail. Best separation of racemic FMB was achieved on cellulose tri(3,5-dimethylphenylcarbamate)-coated CSP with the resolution of 2.50 using the hexane-ethanol mixture (99:1, v/v). Then, each FMB enantiomer was obtained through semi-preparative separation with enantiomeric purity over 99%, and their absolute configurations as well as elution order were determined by electronic circular dichroism spectroscopy. Surprisingly, elution reversal phenomenon of FMB enantiomers was observed on cellulose- and amylose- tri(3,5-dimethylphenyl carbamate)-coated CSPs, in which (S)-FMB was eluted first on cellulose tri(3,5-dimethylphenylcarbamate)-coated CSP, and (R)-enantiomer was eluted first on the other. Moreover, molecular docking simulation has been employed to explain the recognition mechanism and elution reversal of FMB enantiomers on these two CSPs. The docking results revealed that π-π stacks, π-lone pair interactions, π- σ, and π-alkyl interactions between FMB and CSPs were the primary forces driving chiral separation, and the differences between them led to the enantiomer elution reversal on these two CSPs. Briefly, this work would provide valuable information for the separation and elution mechanisms of chiral molecular motors on polysaccharide-based CSPs.
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