Abstract
This is a systematic theoretical gas phase study of the gauche and trans conformers of 1-fluoro-2-haloethanes (FCH2CH2X, X=Cl, Br and I). The methods used are second order Møller-Plesset theory (MP2) and density functional theory (DFT). The basis set used is 6-311++(d,p) for all atoms except that 3-21G and CRENBL ECP are used for iodine atom. The functional used for DFT method is B3LYP. G2/MP2 calculation has also been carried out using MP2 optimised structure. The results indicate that unlike 1,2-difluoroethane, there is the absence of gauche effect and thus there is more preference for the trans conformer. The preference for the more stable trans conformer increases with increasing atomic size of the substituted halogen atom. The same trend is observed for energy difference between the gauche and trans conformers. The 1-fluoro-2-haloethanes have also been subjected to vibrational analysis.
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Dixon, D.A., Matsuzawa, N., Walker, S.C.: Conformational Analysis of 1,2-Dihaloethanes: A Comparison of Theoretical Methods. J. Phys. Chem. 96, 10740–10746 (1992)
Wolfe, S.: The Gauche Effect. Some Stereochemical Consequences of Adjacent Electron Pairs and Polar Bonds. Acc. Chem. Res. 5, 102–111 (1972)
O’Hagan, D., Rzepa, H.S.: Some Influences of Fluorine in Bioorganic Chemistry. Chem. Commun., 643–652 (1997)
Rablen, P.R., Hoffman, R.W., Hrovat, D.A.: Is Hyperconjugation Responsible for the “Gauche Effect” in 1-fluoropropane and 1-fluoroethanes? J. Chem. Soc. Perkin Trans. 2(8), 1719–1726 (1999)
O’Hagan, D., Bilton, C., Howard, J.A.K., Knight, L., Tozer, D.J.: The Preferred Conformation of N-β-fluoroethylamides. Observation Fluorine Amide Gauche Effect. J. Chem. Soc. Perkin. Trans. 2(8), 600–607 (2000)
Tavasli, M., O’Hagan, D., Pearson, C., Petty, M.C.: The Fluorine Gauche Effect. Langmuir Isothems Reprot the Relative Conformational Stability of (+/-)-Erythro- and (+/-)-Threo-9,10-Difluorostearic acids. Chem. Commun. 7, 1226–1227 (2002)
Briggs, C.R., Allen, M.J., O’Hagan, D., Tozer, D.J., Slawin, A.M., Geota, A.E., Howard, J.A.: The Observation of a Large Gauche Preference when 2-Fluoroethylmanine and 2-Fluoroethanol Become Protonated. Org. Biomol. Chem. 2, 732–740 (2004)
Banks, J.W., Batsanov, A.S., Howard, J.A.K., O’Hagan, D., Rzepa, H.S., Martin-Santamaria, S.: The Preferred Conformation of α-Fluoroamides. J. Chem. Soc., Perkin Trans. 2(8), 2409–2411 (1999)
Wiberg, K.B., Murcko, M.A., Laidig, E.K., MacDougall, P.J.: Origin of the “Gauche Effect” in Substituted Ethanes and Ethenes. The Gauche Effect. J. Phys. Chem. 96, 6956–6959 and references therein (1992)
Harris, W.C., Holtzclaw, J.R., Kalasinsky, V.F.: Vibrational Spectra and Structure of 1,2-Difluoroethane: Gauche-Trans Conformers. J. Chem. Phys. 67, 3330–3338 (1977)
Friesen, D., Hedberg, K.: Conformational Analysis. 7. 1,2-Difluoroethane. An Electron-Diffraction Investigation of the Molecular Structure, Composition, Trans-Gauche Energy and Entropy Differences, and Potential Hindering Internal Rotation. J. Am. Chem. Soc. 102, 3987–3994 (1980)
Takeo, H., Matsumura, C., Morino, Y.: Microwave Spectrum and Molecular Structure of Gauche-1,2-Difluoroethane. J. Chem. Phys. 84, 4205–4210 (1986)
Martell, J.M., Boyd, R.J.: An Ab initio Study of the Series C2 H n F6 − n (n=0-6): Geometries, Total Energies, and C-C Bond Dissociation Energies. J. Phys. Chem. 96, 6287–6290 (1992)
Durig, J.R., Liu, J., Little, T.S., Kalasinsky, V.F.: Conformational Analysis, Barriers to Internal Rotation, Vibrational Assignment, and Ab Initio Calculations of 1,2-Difluoroethane. J. Phys. Chem. 96, 8224–8233 (1992)
Wiberg, K.B., Keith, T.A., Frisch, M.J., Murcko, M.: Solvent Effects on 1,2-Dihaloethane Gauche/Trans Ratios. J. Phys. Chem. 99, 9072–9079 (1995)
Ramasami, P.: Gauche and Trans Conformers of 1,2-Dihaloethanes: A Study by Ab Initio and Density Functional Theory Methods. Lecture Series on Computer and Computational Sciences, vol. 1, pp. 732–734. Brill Academic Publishers, The Netherlands (2005)
Gaussian 03, Revision C.02, Frisch M.J., Trucks G.W., Schlegel H.B., Scuseria G.E., Robb M.A., Cheeseman J.R, Montgomery J.A., Jr., Vreven T., Kudin K.N., Burant J.C., Millam J.M., Iyengar S.S., Tomasi J., Barone V., Mennucci B., Cossi M., Scalmani G., Rega N., Petersson G.A., Nakatsuji H., Hada M., Ehara M., Toyota K., Fukuda R., Hasegawa J., Ishida M., Nakajima T., Honda Y., Kitao O., Nakai H., Klene M., Li X., Knox J.E., Hratchian H.P., Cross J.B, Bakken V., Adamo C., Jaramillo J., Gomperts R., Stratmann R.E., Yazyev O., Austin A.J., Cammi, R. Pomelli C., Ochterski J.W., Ayala P.Y., Morokuma K., Voth G.A., Salvador P., Dannenberg J.J., Zakrzewski V.G., Dapprich S., Daniels A.D., Strain M.C., Farkas O., Malick D.K., Rabuck A.D., Raghavachari K., Foresman J.B., Ortiz J.V., Cui Q., Baboul A.G., Clifford S., Cioslowski J., Stefanov B.B., Liu G., Liashenko A., Piskorz P., Komaromi I., Martin R.L., Fox D.J., Keith T., Al-Laham M.A., Peng C.Y., Nanayakkara A., Challacombe M., Gill P.M.W., Johnson B., Chen W., Wong M.W., Gonzalez C., Pople J.A.: Gaussian, Inc., Wallingford, CT (2004)
Hurley, M.M., Pacios, L.F., Christiansen, P.A., Ross, R.B., Ermler, W.C.: Ab Initio Relativistic Effective Potentials with Spin-Orbit Operators. II. K through Kr. J. Chem. Phys. 84, 6840–6853 (1986)
Durig, J.R., Pan, C., Witkowski, W., Guirgis, G.A.: Conformational Stability, Infrared and Raman spectra, and Vibrational assignment of Ethyl Bromogermane. Can. J. Chem. 82, 964–977 (2004)
Tanabe, K.: Calculation of Infrared Band Intensities and Determination of Energy Differences of Rotational Isomers of 1,2-Dichloro-, 1,2-Dibromo- and 1-Chloro-2-Bromoethane. Spectrochim. Acta 28, 407–424 (1972)
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Ramasami, P. (2006). Theoretical Gas Phase Study of the Gauche and Trans Conformers of 1-Fluoro-2-Haloethanes CH2F-CH2X (X=Cl, Br, I) by Ab Initio and Density Functional Methods: Absence of Gauche Effect. In: Alexandrov, V.N., van Albada, G.D., Sloot, P.M.A., Dongarra, J. (eds) Computational Science – ICCS 2006. ICCS 2006. Lecture Notes in Computer Science, vol 3993. Springer, Berlin, Heidelberg. https://doi.org/10.1007/11758532_22
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