Abstract
A previously developed scheme for describing the diamagnetic characteristics of molecules with conjugated bonds has been generalized to the case of noncoplanar systems, and the1H and13C chemical shifts of the benzyl, diphenylmethyl, triphenylmethyl, and α- and β-naphthyl anions and cations have been calculated on its basis and compared with experiment. It has been shown that the current contributions to the magnetic shielding for the anions and cations of odd alternant hydrocarbons of identical structure and charge multiplicity are equal to one another, while the charge contributions differ in sign. This has made it possible to find the “experimental” charge distribution of the cations investigated and to compare it with the results of quantum-chemical calculations.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Literature cited
Yu. B. Vysotskii, “Magnetic characteristics of polycyclic hydrocarbons,” Zh. Strukt. Khim.,15, No. 1, 56–63 (1974).
Yu. B. Vysotskii, “Influence of π-electronic charges on the magnetic properties of molecules.“ ibid.,15, No. 3, 566–572 (1974).
Tu. B. Vysotskii, “π-Electronic ring currents, proton magnetic shielding, and diamagnetic susceptibility of azoles in the MO-LCAO-SCF method,” ibid.,19, No. 4, 605–612 (1978).
A. K. Sheinkman, M. M. Mestechkin, A. P. Kucherenko, et al., “Reactions of cyclammonium cations. 29. Influence of annelation on the reactivity of benzoquinolines in hetarylation reactions,” Khim. Geterotsikl. Soedin., NO. 8, 1096–1105 (1974).
Yu. B. Vysotskii (Vysotsky), V. A. Kuzmitskii (Kuzmitsky), and K. N. Solovyov, “π-Electron ring currents and magnetic properties of porphyrin molecules in the MO-LCAO-SCF method,” Theor. Chim. Acta,59, No. 5, 467–485 (1981).
Yu. B. Vysotskii, B. P. Zemskii, E. N. Zemskaya, and N. N. Aleksee, “Spectroscopic characteristics of sulfur-containing heterocycles in the MO-LCAO-SCF method,” Zh. Strukt. Khim.,22, No. 3, 13–21 (1981).
Yu. B. Vtsotskii and L. N. Sivyakova, “π-Electronic ring currents and magnetic shielding in oxygen-containing unsaturated heterocyclic systems,” Teor. Éksp. Khim.,21, No. 3, 293–302 (1985).
M. M. Mestechkin, Density-Matrix Method in Molecular Theory [in Russian], Naukova Dumka, Kiev (1977).
Yu. B. Vysotskii, “Calculation of molecular magnetic properties in the Hartree-Fock method,” Zh. Strukt. Khim.,13, No. 3, 498–606 (1972).
M. M. Mestechkin and L. S. Gutyrya, “Methods for calculating the spin density and other properties of molecular systems,” Teor. Éksp. Khim.,10, No. 1, 16–25 (1974).
A. Bickstock and J. A. Pople, “Resonance energies and charge distributions of unsaturated hydrocarbon molecules and radicals,” Trans. Faraday Soc.,50, No. 9, 901–911 (1954).
D. Bethell and V. Gold, Carbonium Ions, an Introduction, Academic Press, New York (1967).
B. Ancian, J.-P. Doucet, and J.-E. Dubois, “Electronic structure of substituted diphenylmethylcarbenium ions. A proton magnetic resonance and MO-INDO study,” J. Am. Chem. Soc.,98, No. 16, 4764–4769 (1976).
K. Takahashi, Y. Kondo, and R. Asami, “Carbon-13 NMR spectra of arylmethyl carbanion,” Org. Magn. Reson.6, No. 11 580–582 (1974).
R. N. Young, “NMR spectroscopy of carbanion and carbocations,” Prog. NMR Spectrosc.,11, 1–137 (1979).
G. J. Ray, R. J. Kurland, and A. K. Colter, “Magnetic resonance studies of triphenylcarbonium ions. 2. Carbon-13 magnetic resonance studies of charge delocalization in para-substituted triphenylcarbonium ions,” Tetrahedron,27, No. 4, 735–752 (1971).
V. R. Sandel and H. H. Freedman, “π-Electron densities in arylmethyl carbanions by nuclear magnetic resonance spectroscopy,” J. Am. Chem. Soc.,85, No. 15, 2328–2329 (1963).
R. S. Berry, R. Dehl, and W. R. Vaughan, “Nuclear magnetic resonance spectrum of the triphenylcarbonium ion,” J. Chem. Phys.,34, No. 4, 1460–1461 (1961).
K. Takahashi, M. Takaki, and R. Asami, “Nuclear magnetic resonance spectrum of carbanions, Org. Magn. Reson.,3, No. 5, 539–543 (1971).
J. B. Grutztner, J. M. Lawlor, and M. M. Jackman, “Studies in magnetic resonance. 10. The spectroscopy of carbanions and the effect of ion pairing on chemical shifts,” J. Am. Chem. Soc.,94, No. 7, 2306–2317 (1972).
R. J. Hunadi, Methano-bridged 14n-electron aromatic annulenes. 3. Carbon-13 nuclear magnetic resonance spectroscopic study of the 1,6-methanofluorenyl anion and comparison with the related 1,6-methanocudenyl and fluorenyl anions,” J. Org. Chem.,47, No. 10, 1940–1944 (1982).
G. A. Olah, “Stable carbonium ions. 6. NMR investigation of the diphenylcarbonium, and phenyldimethylcarbonium ions,” J. Am. Chem. Soc.,86, No. 5, 932–934 (1964).
G. A. Olah, P. W. Westerman, and I. Nishimura,” Stable carbocations. 164. The relative ability of charge delocalization by phenyl, cyclopropyl, and methyl groups in carbonium ions,”96, No. 11, 3548–3559 (1974).
D. E. O'Reilly and H. P. Leftin, “Nuclear magnetic resonance spectra of the triphenylcarbonium and methyldiphenylcarbonium ion,” J. Phys. Chem.,64, No. 10, 1555–15559 (1960).
L. Zetta and G. Gatti, “1H and13C NMR spectra of the benzyl compounds,” Org. Magn. Reson.,4, No. 4, 585–589 (1972).
Yu. B. Vysotskii, “13C chemical shifts and antiaromaticity of the dianion and dication of anthracene,” Zh. Org. Khim.,14, No. 7, 1563 (1978).
Author information
Authors and Affiliations
Additional information
Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 3, pp. 277–283, May–June, 1989.
Rights and permissions
About this article
Cite this article
Vysotskii, Y.B., Sivyakova, L.N. Pairing theorem and magnetic shielding of cations and anions of odd alternant hydrocarbons. Theor Exp Chem 25, 253–259 (1989). https://doi.org/10.1007/BF01299000
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01299000