Intrinsic Chirality and Prochirality at Air/R‐(+)‐ and S‐(–)‐Limonene Interfaces: Spectral Signatures With Interference Chiral Sum‐Frequency Generation Vibrational Spectroscopy

• DOI: 10.1002/chir.22337
• Publication Date: 2014-06-04T07:49:10Z
• Authors: Li Fu; Yun Zhang; Zhe‐Hao Wei; Hong‐Fei Wang
• Keywords: Chirality; Diastereomer

We report in this work detailed measurements of the chiral and achiral sum-frequency vibrational spectra C-H stretching vibration region (2800-3050 cm(-1)) air/liquid interfaces R-(+)-limonene S-(-)-limonene, using recently developed high-resolution broadband generation spectroscopy (HR-BB-SFG-VS). The SFG R-limonene S-limonene, as well RS racemic mixture (50/50 equal amount mixture), show that corresponding molecular groups R S enantiomers are with same interfacial orientations. interference limonene exhibit a spectral signature from response Cα-H mode, prochiral CH(2) asymmetric respectively. feature mode changes sign to S-(-)-limonene surfaces, disappears for surface. While is also surprisingly remains Therefore, structures at liquid nevertheless not mirror images each other, even though have tilt angle normal, i.e., surface diastereomeric instead enantiomeric. These results provide information understanding structure chirality demonstrate sensitivity potential SFG-VS unique spectroscopic tool characterization recognition interface.