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.
W.Caminati, J.-U.Grabow (2006). The C2v structure of enolic acetylacetone. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 128, 854-857 [10.1021/ja055333g].
The C2v structure of enolic acetylacetone
CAMINATI, WALTHER;
2006
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
