Optical properties of cyclic dimers of amino acids: An experimental and theoretical study
CD spectra have been measured in the vacuum‐uv region to about 135 nm for cyclo(Lalanyl‐glycine), cyclo(Lalanyl‐L‐alanine), and cyclo(L‐prolyl‐L‐proline). In addition to the amide CD bands usually observed at wavelengths longer than 180 nm, a Independent systems calculations show that these intense short‐wavelenght bands can be attributed to σσ* transitions of the backbone. Transitions of the amide chromophore expected at wavelenghts shorter than 180 nm cannot account for the observed CD. Copyright © 1983 John Wiley & Sons, Inc.