Circular dichroism spectrum dispersion effect

Figure 5. Circular dichroism spectrum for a micellar suspension of AmB in water. Data collected on a JASCO J-600. Curve 1 shows the original spectrum and curve 2 the effect of adding cyclosophorans to the AmB dispersion.

When an enantiomer of CSA is used in the polymerization, such as R-CSA, it is possible to create chiral polyaniline nanofibers. Figure 7.20 shows the circular dichroism (CD) spectrum of a water dispersion of as-prepared R-CSA doped polyaniline nanofibers. The positive peak at 450 nm is characteristic of chiral polyaniline [66-70], and is consistent with water s effect on the direction of the CD signals previously observed [71]. The peak at 290 nm is due to excess R-CSA in the dispersion. Recently, Wang et al. discovered that highly chiral polyaniline nanofibers can be produced by incremental addition of the oxidant, ammonium peroxydisulfate, into aniline solution with aniline oligomers and concentrated chiral dopants (>5 M R- or S-CSA) [72]. Chiral polyaniline nanofibers are very interesting for chiral recognition studies [68]. 

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