ASSIGNMENT OF ABSOLUTE-CONFIGURATIONS FROM THE CIRCULAR-DICHROISM SPECTRA OF CYCLIC ETA-4-DIENE COMPLEXES OF FE(CO)3

The circular dichroism spectra of a set of 1-substituted tricarbonyl(eta-4-cyclohexadiene)iron(0) complexes with comparable absolute configurations reveal a pattern of bands that correlates with the absolute stereochemistry of the complexes; the nature of the substituents attached at C-1 of the diene is important in the interpretation of the CD spectra of these compounds, since the sign of the highest wavelength band can be reversed for a particular absolute configuration, depending on whether electron-donating or electron-withdrawing substituents are present.