Chiroptical properties of five-co-ordinated olefin complexes of platinum (II)

Abstract

The chiroptical properties of five-co-ordinated complexes of general formula [PtCl₂(N–N)(olefin)], with olefin ligands having either electron-donating or electron-withdrawing substituents, have been investigated. A comparison is also made with related square-planar complexes. The optical properties and the c.d. spectra of several enantiomers are reported. A correlation rule between the sign of the c.d. bands in the regions around 29 000 and 44 000 cm^–1 and the absolute configuration is found for complexes containing prochiral ethylene homologues. For both bands a positive sign seems to be diagnostic for the R configuration.