Polymers, Colloids and Interfaces, Poster
Resonance Raman Optical Activity of Single Walled Carbon Nanotube Enantiomers
M. Magg1, P. Oulevey1, T. Bürgi1*
1University of Geneva
Single Walled Carbon Nanotubes (SWCNTs) are, except for zigzag and armchair configurations, helically chiral nanostructures. As such, they exist in two enantiomeric forms which may be denoted as P and M according to the sense of their helix. Little attention has been paid so far to investigate the properties of SWCNT enantiomers owing to the difficulty to prepare enantio-enriched SWCNT samples.[1]
We present continuous work on Raman Optical Activity (ROA) as a new technique to characterize the structure and handedness of SWCNTs.[2] Experimental spectra at 532 nm on highly purified (6,5)-SWCNTs were recorded. Spectra are found to be in agreement with the single-excited-state theory (SES). Strong enhancement of the G-band is found which is in line with strong resonance between the Stokes-shifted photon and the electronic E22S transition. As calculation of resonance ROA for SWCNTS is not practical, predicted resonance ROA spectra on smaller conjugated chiral carbon systems are performed. In general, Raman spectroscopy is not limited to solution based measurements, but also provides the opportunity to characterize chiral films of SWCNTs.
[1] Saunab Gosh, Sergei M. Bachilo, Bruce R. Weisman, Nature Nanotechnology, 2010, 5, 443
[2] Martin Magg, Yara Kadria-Vili, Patric Oulevey, Buce R. Weisman and Thomas Bürgi, J. Phys Chem. Lett., 2016, 7, 221 <