@article {2281,
	title = {Structure and vibrational assignment of the enol form of 1-chloro-1,1 difluoro-pentane-2,4-dione},
	journal = {J. Mol. Struct.},
	volume = {878},
	number = {1-3},
	year = {2008},
	note = {ISI Document Delivery No.: 300CGTimes Cited: 0Cited Reference Count: 42Tayyari, Sayyed Faramarz Najafi, Atefeh Afzali, Raheleh Emamian, Saeedreza Wang, Yan Alexander},
	month = {Apr},
	pages = {10-21},
	type = {Article},
	abstract = {<p>Molecular structure of 1-chloro-1,1-difluoro-pentane-2,4-dione (monochlorodifluoro-acetylacetone, CDFAA) has been investigated by means of ab initio and Density Functional Theory (DFT) calculations and the results were compared with those of 1,1,1-trifluoropentane-2,4-dione (trifluoro-acetylacetone, TFAA). The harmonic vibrational frequencies of the two most stable cis-enol forms were calculated at the 133LYP level of theory using 6-3 1 G** and 6-311 ++G** basis sets. We also calculated the anharmonic frequencies at the B3LYP/6-31G** level of theory for these two stable cis-enol isomers. The calculated frequencies and the Raman and IR intensities were compared with the experimental results. The energy difference between the two stable cis-enol forms, calculated at the MP2/6-31G** level, is only 3.42 U/mol. The observed vibrational frequencies and intensities in the gas phase are in excellent agreement with the corresponding values calculated for the two most stable conformers. However, the observed IR and Raman frequencies also indicate coexisting of both tautomers in the liquid phase and in solution. According to the theoretical calculations, at the B3LYP/6-31 1++G** level, the hydrogen bond strength for the most stable conformer is 54.45 U/mol, about 2.4 kJ/mol less than that of the corresponding conformer of TFAA. These results are in agreement with the obtained experimental data. (C) 2007 Elsevier B.V. All rights reserved.</p>},
	keywords = {1-chloro-1, 1-difluoro-pentane-2, 4-dione, AB-INITIO, anharmonicity, BETA-DIKETONES, density, ELECTRON-DIFFRACTION, ENERGY, EQUILIBRIUM, functional theory, HEXAFLUORO-ACETYLACETONE, intramolecular hydrogen bond, MALONALDEHYDE, MOLECULAR-STRUCTURE, TAUTOMERISM, vibrational spectra},
	isbn = {0022-2860},
	url = {<Go to ISI>://000255801300002},
	author = {S. F. Tayyari* and Najafi, A. and Afzali, R. and Emamian, S. and Wang, Y. A.}
}
@article {1592,
	title = {Conformational stability, molecular structure, and intramolecular hydrogen bonding of thenoyltrifluoroacetone},
	journal = {J. Theor. Comput. Chem.},
	volume = {5},
	number = {3},
	year = {2006},
	note = {ISI Document Delivery No.: 098FUTimes Cited: 3Cited Reference Count: 52Tayyari, Sayyed Faramarz Nekoei, Abdo-Reza Vakili, Mohammad Hassanpour, Masoud Wang, Yan Alexander},
	month = {Sep},
	pages = {647-664},
	type = {Article},
	abstract = {<p>Complete conformational analysis of all possible keto and enol forms of thenoyltrifluoroacetone (TTFA) was carried out using density functional theory with the B3LYP functional and the 6-31G**, 6-311G**, and 6-311++G** basis sets. In addition, the geometries and energies of the four most stable chelated conformers and their corresponding open structures were obtained at the MP2/6-31G** level of theory. The energy differences between the four stable chelated enol conformers, in the gas phase, calculated at the B3LYP levels are negligible. However, calculations at the MP2 level indicate that the B2 conformer (the hydroxyl group in the -CF3 side) is significantly more stable than others, in agreement with the X-ray diffraction results. The calculated intramolecular hydrogen bond (IHB) energy E-HB and the strength of the bond have been compared, and an imperfection in the prevalent method of evaluating E-HB has been perceived. The IHB of TTFA was compared with those in several beta-dicarbonyls.</p>},
	keywords = {ACETYLACETONE, beta-diketone, BETA-DIKETONES, conformational analysis, CRYSTAL-STRUCTURE, EQUILIBRIUM CONSTANTS, INFRARED-SPECTRA, intramolecular hydrogen bond, KETO-ENOL-TAUTOMERISM, nuclear magnetic resonance, PROTON CHEMICAL, SHIFTS, SYNERGISTIC EXTRACTION, thenoyltrifluoroacetone, VIBRATIONAL ASSIGNMENT},
	isbn = {0219-6336},
	url = {<Go to ISI>://000241507200011},
	author = {S. F. Tayyari* and A.-R. Nekoei and Vakili, M. and Hassanpour, M. and Wang, Y. A.}
}
