ESR and Optical Studies on the Interaction between cis-Dichlorodiammine Platinum(II) and Tryptophan

Abstract
Cis-Dichlorodiammine platinum(II), an active anticancer compound, and tryptophan form paramagnetic complexes in aqueous solution. These can be detected by means of ESR after a reaction time of several hours. The ESR spectra are interpreted to be due to Pt(III) in a low spin d7 configuration. The optical results obtained are in accordance with the assumption of columnar structures of the paramagnetic complexes.