The C2v Structure of Enolic Acetylacetone
journal contributionposted on 25.01.2006, 00:00 by Walther Caminati, Jens-Uwe Grabow
It has often been postulated that the lowest energy enolic form of Acetylacetone (AcAc) assumes Cs symmetry, i.e., has a double-minimum potential possibly exhibiting a low barrier to internal proton transfer and not a single minimum, C2v. Recent theoretical calculations and experimental work support the Cs hypothesis but the literature on this fascinating molecule is divided. Toward this objective, the high-resolution rotational spectra of enolic acetylacetone and 3 isotopologues have been obtained, revealing C2v symmetry. The two methyl groups exhibit a very low barrier to internal rotation, thus making AcAc internally highly dynamic.