Circular dichroism and absorption spectra of chiral ketone. I2 complexes in solution

Abstract

Difference absorption spectroscopy in the visible spectral region is used to investigate the formation of electron donor–acceptor (EDA) complexes between I₂ and a series of chiral ketone compounds dissolved in chloroform. Evidence for 1 : 1 complex formation is found for the camphor + I₂ and camphorquinone + I₂ systems. The camphor + I₂ complex exhibits a relatively strong circular dichroism (CD) band in the region of a “perturbed” molecular iodine transition (∼498 nm), and the visible CD spectrum of camphorquinone + I₂ also shows evidence of induced optical activity in the bound I₂ transitions.