(Vibrational) Circular dichroism

• No Reaxys property search code!
• The Vibrational spectrum recorded with polarised light
  • Demonstrated in 1976 (Review: 2003 or 2011). Routine FT-IR from ~1995 onwards.
  • The vibrational Cotton effect!
• The VCD spectra (and Cotton effects) of two enantiomers are mirror images.
  • The sign of the Cotton effect defines the absolute configuration
• No reliable empirical rules
  • Much easier to associate with local structures/bonds/stereogenic centres