Photochemische Synthese von Pinocarvon-, Pulegon- und Benzalacetophenon-tricarbonyleisen. Ein Beitrag zur Frage der Bindung α, β-ungesättigter Ketone in Eisen-Komplexen / Photochemical Synthesis of Pinocarvone-, Pulegone-, and Benzalacetophenone-tricarbonyliron. A Contribution to the Nature of Bonding in Iron-Complexes of α,β-unsaturated Ketones

Abstract
The photochemical synthesis of the title compounds is described. It has been established by spectroscopic evidence and by the x-ray structure of pinocarvone tricarbonyliron that in all these cases bonding to the iron involves only the π-system of the α,β-unsaturated ketones and not the nonbonding electrons of the keto group. The preferential site of monodentate coordination of α,β-unsaturated carbonyl compounds to transition metals is discussed on the basis of MO-considerations which are extended to 1,2-dicarbonyl compounds.