Differently from acetylacetone, hexafluoroacetylacetone is a “rigid” molecule on the scale time of microwave spectroscopy. Its rotational spectrum, corresponding to the enolic Cs form, does not display any doubling of rotational lines, indicating high effective barriers to the internal motions. An accurate structure of the main frame of the molecule has been obtained from the rotational spectra of nine isotopic species, measured by pulsed jet Fourier transform microwave spectroscopy. The keto form lies, according to MP2/6-311++G(d,p) ab initio calculations, about 14 kJ/mol higher in energy.
L. Evangelisti, S. Tang, B. Velino, B. M. Giuliano, S. Melandri, W.Caminati (2009). Hexafluoroacetylacetone: a “rigid” molecule with an enolic Cs shape. CHEMICAL PHYSICS LETTERS, 473, 247-250 [10.1016/j.cplett.2009.03.080].
Hexafluoroacetylacetone: a “rigid” molecule with an enolic Cs shape
EVANGELISTI, LUCA;VELINO, BIAGIO;GIULIANO, BARBARA MICHELA;MELANDRI, SONIA;CAMINATI, WALTHER
2009
Abstract
Differently from acetylacetone, hexafluoroacetylacetone is a “rigid” molecule on the scale time of microwave spectroscopy. Its rotational spectrum, corresponding to the enolic Cs form, does not display any doubling of rotational lines, indicating high effective barriers to the internal motions. An accurate structure of the main frame of the molecule has been obtained from the rotational spectra of nine isotopic species, measured by pulsed jet Fourier transform microwave spectroscopy. The keto form lies, according to MP2/6-311++G(d,p) ab initio calculations, about 14 kJ/mol higher in energy.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
