Abstract
Methods developed previously for calculating the magnetic characteristics of molecules have been used to evaluate the19F chemical shifts in a number of perfluorinated cyclopolyenes, fluorobenzenes and fluoronaphthalenes. It is shown that the magnetic shielding of the19F nucleus is determined by the π-electron densities on the fluorine atoms, and that the contributions of the induced π-electron ring currents can be neglected. The calculated results are compared with experiment.
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Literature cited
J. W. Emsley, J. Feeney, and L. A. Sutcliffe, High Resolution Nuclear Magnetic Resonance Spectroscopy [Russian translation], Izd. Mir, Moscow (1968), Vol. 1.
V. K. Mukhomorov, “Calculation of19F Chemical shifts in ortho-substituted fluorobenzenes,” Teor. Eksp. Khim.,8, No. 5, 651–657, (1972).
V. K. Mukhomorov, “Calculation of19F chemical shifts in polysubstituted derivatives of fluorobenzene,” Teor. Éksp. Khim.,10, No. 5, 685–687 (1974).
J. F. Emsley, “The relationship between charge density and the chemical shifts of fluorine nuclei in aromatic compounds,” J. Chem. Soc. A, No. 8, 2018–2011 (1968).
T. K. Wu and T. P. Das, “Chemical shifts and pi-electron densities in substituted benzenes,” J. Chem. Phys.,41, No. 7, 2796–2806 (1964).
P. B. Sargeant and C. G. Krespan, “Fluorocyclopropanes. 2. Synthesis, properties and reactions of perfluorocyclopropene,” J. Am. Chem. Soc.,91, No. 2, 415–419 (1969).
G. Paprott and K. Seppelt, “Perfluorocyclopentadienyl anions, C5F5 Ś,” J. Am. Chem. Soc.,106. No. 14, 4060–4061 (1984).
M. J. S. Dewar and J. Kelemen, “Ground states of conjugated molecules. 10.19F chemical shifts in aryl fluorides,” J. Chem. Phys.,49, No. 2, 499–508 (1968).
W. P. Dailey and D. M. Lemal, “Perfluorotropylidene valence isomers and the perfluorotropylium ion,” J. Am. Chem. Soc.,106, No. 4, 1169–1171 (1984).
W. P. Dailey, “The relationship between19F chemical shifts and calculated electron densities in perfluorinated annulens,” Tetrahedron Lett.,27, No. 25, 2825–2828 (1986).
Yu. B. Vysotskii, “The calculation of molecular magnetic properties in the Hartree-Fock method,” Zh. Strukt. Khim.,13, No. 3, 498–506 (1972).
Yu. B. Vysotskii and M. M. Mestechkii, “The effect of π-electron currents on13C chemical shifts,” Zh. Strukt. Khim.,16, No. 2, 303–305 (1975).
Yu. B. Vysotskii and L. N. Sivyakova, “π-Electron ring currents and magnetic shielding in in unsaturated heterocycles containing oxygen,” Teor. Ekxp. Khim.,21, No. 3, 293–302 (1985).
Yu. B. Vysotskii, “The calculation of the magnetic shielding of nitrogen nuclei,” Zh. Strukt. Khim.,19, No. 4, 736–738 (1978).
M. M. Mestechkin, The Density Matrix Method in Molecular Theory“ [in Russian], Nauk. Dumka, Kiev (1977).
J. C. Schug, “Optimum parametrization in SCF pi-electron theory,” Mol. Phys.,19, No. 1, 121–130 (1970).
K. Hirayama, Handbook of Ultraviolet and Visible Absorption Spectra of Organic Compounds, Plenum Press, New York (1967).
H. Spiesecke and W. G. Schneider, “Substituent effects on the13C and1H chemical shifts in monosubstituted benzenes,” J. Chem. Phys.,35, No. 2, 731–738 (1961).
E. M. Schulman, K. A. Christensen, D. M. Grant, and C. Walling, “Substituent effects on carbon-13 chemical shifts in 4-substituted biphenyls and benzenes,” J. Org. Chem.,39, No. 18, 2686–2690 (1974).
W. F. Bailey, E. A. Cioffi and K. B. Wiberg, “Resonance Spectroscopy. 2. Factor analysis of carbon-13 chemical shifts in unsaturated and aromatic halides,” J. Org. Chem.,46, No. 21, 4219–4225 (1981).
M. A. Cooper, H. E. Weber, and S. L. Manutt, “The fluorine-19 NMR spectra of some fluoroaromatic compounds,” J. Am. Chem. Soc.,93, No. 10, 2369–2380 (1971).
R. Bolton and J. P. B. Sandall, “Nucleophilic displacement in polyhalogenoaromatic compounds,” J. Chem. Soc. Perkin Trans. II, No. 13, 1541–1548 (1976).
L. V. Vlasova, L. S. Kobrina, and N. V. Popkova, “Synthesis and19F NMR spectra of some substituted fluoronaphthalenes,” Izv. Sib. Otd. Akad. Nauk SSSR. Ser. Khim., No. 4/2, 112–120 (1974).
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Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 3, pp. 344–348, May–June, 1989.
The Authors express their thanks to A. N. Simonenko and E. YU. Balabanov for assistance with the calculations.
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Vysotskii, Y.B. Ring currents and π-electron charges in the calculation of19F chemical shifts. Theor Exp Chem 25, 319–323 (1989). https://doi.org/10.1007/BF01299012
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DOI: https://doi.org/10.1007/BF01299012