The importance of the localization of the π-electron system on its ability to transmit the fermi contact term of HH coupling constants. A theoretical and experimental study
Semiquantitative relationships between the localization of a π-electron system and its capacity to contribute to the spin-spin coupling constants are found theoretically and experimentally. Theoretically, enlargements of the INDO basis set and the tautomeric structures of 2-hydroxypyridine are used....
| Autor principal: | |
|---|---|
| Otros Autores: | , , , |
| Formato: | Capítulo de libro |
| Lenguaje: | Inglés |
| Publicado: |
1983
|
| Acceso en línea: | Registro en Scopus DOI Handle Registro en la Biblioteca Digital |
| Aporte de: | Registro referencial: Solicitar el recurso aquí |
| Sumario: | Semiquantitative relationships between the localization of a π-electron system and its capacity to contribute to the spin-spin coupling constants are found theoretically and experimentally. Theoretically, enlargements of the INDO basis set and the tautomeric structures of 2-hydroxypyridine are used. Experimentally, the long-range HH coupling constants in 6-methyl-2-pyridone are compared with the corresponding couplings in 2-X-6-methylpyridines (X = amino, formyl, cyano). Evidence shows that the π-contribution to the HH coupling constants is greater when the localization of this electron system is increased. © 1983. |
|---|---|
| Bibliografía: | Pople, Schneider, Bernstein, (1959) High Resolution NMR Spectroscopy, , McGraw-Hill, New York Lee, Schulman, (1979) J. Am. Chem. Soc., 101, p. 3182 Lee, Schulman, (1980) J. Am. Chem. Soc., 102, p. 5184 Emsley, Feeney, Sutcliffe, (1965) High Resolution NMR Spectroscopy, , Pergamon, Oxford Murrell, Chapter 1 The theory of nuclear spin-spin coupling in high resolution NMR spectroscopy (1971) Progress in Nuclear Magnetic Resonance Spectroscopy, 6, p. 1 Barfield, Chakrabarti, (1969) Chem. Rev., 69, p. 757 Kowalewski, (1977) Prog. NMR Spectrosc., 11, p. 1 Kowalewski, Laaksonen, Saunders, (1981) J. Chem. Phys., 74, p. 2412 Laaksonen, Kowalewski, (1981) J. Am. Chem. Soc., 103, p. 5277 Pople, Beveridge, (1970) Approximate Molecular Orbital Theory, , McGraw-Hill, New York Bacon, Maciel, A study of proton-proton coupling constants incis,cis-1,4-dialkyl-1,3-butadienes (1971) Molecular Physics, 21, p. 257 Steiger, Gey, Radeglia, Zur Berechnung des π-Beitrages zu den H,H-Kopplungskonstanten von Vinylverbindungen (1975) Molecular Physics, 30, p. 1729 Fukui, Tsuji, Miura, (1981) J. Am. Chem. Soc., 103, p. 3652 Engelmann, Contreras, Facelli, (1981) Theor. Chim. Acta, 59, p. 17 Engelmann, Contreras, (1982) QCPE Bull., 2, p. 14 Engelmann, Scuseria, Contreras, (1982) J. Magn. Reson., 50, p. 21 Facelli, Giribet, Contreras, The use of partially restricted molecular orbitals to investigate transmission mechanisms of spin-spin coupling constants. III—an INDO study of long-range FH couplings in fluorinated derivatives of toluene (1982) Organic Magnetic Resonance, 19, p. 138 de Kowalewski, Contreras, Engelmann, Facelli, Durán, Transmission mechanisms of inter-proton long-range couplings in substituted anisoles (1981) Organic Magnetic Resonance, 17, p. 199 A. R. Engelmann and R. H. Contreras, Int. J. Quantum Chem., in press; Barfield, Chakrabarti, (1969) J. Am. Chem. Soc., 91, p. 4346 Macdonald, Reynolds, Signs of methyl–methyl proton spin–spin coupling constants in xylene derivatives (interbenzylic coupling) (1970) Canadian Journal of Chemistry, 48, p. 1002 Wasylishen, Schaefer, INDO Molecular Orbital Calculations on the Conformational Dependence of Long-range Spin–Spin Coupling of Methyl Protons in Toluene,p-Fluorotoluene, and the Xylenes (1972) Canadian Journal of Chemistry, 50, p. 1852 Kowalewski, Contreras, (1972) J. Magn. Reson., 8, p. 101 Pople, Beveridge, Dobosh, (1967) J. Chem. Phys., 47, p. 2026 Cordell, Boggs, (1981) J. Mol. Struct., 85, p. 163. , Theochem Facelli, Contreras, Inclusion of hydrogenp orbitals in the semiempirical calculation of NMR parameters. I. Influence on the FPT INDO spin-spin coupling constants (1980) International Journal of Quantum Chemistry, 18, p. 1175 Facelli, Contreras, Inclusion of hydrogenp orbitals in the semiempirical calculation ofNMR parameters. III:INDO CHF calculations of orbital and dipolar contributions to spin-spin coupling constants involving protons (1981) International Journal of Quantum Chemistry, 20, p. 909 Facelli, Contreras, (1981) J. Mol. Struct., 85, p. 99. , Theochem Ostlund, (1972) QCPE, 9, p. 224. , program FINITE Bak, Hansen-Nygaard, Rastrup-Andersen, (1958) J. Mol. Spectrosc., 2, p. 361 Pople, Gordon, (1967) J. Am. Chem. Soc., 89, p. 4253 Pople, McIver, Ostlund, (1966) Chem. Phys. Lett., 1, p. 272 Pople, McIver, Ostlund, (1968) J. Chem. Phys., 49, p. 2960 Brugel, (1979) Handbook of NMR Spectral Parameters, , Heyden, London Facelli, Contreras, Scuseria, Engelmann, (1979) J. Mol. Struct., 57, p. 299 Rowbotham, Schaefer, Sigma and Pi Electron Contributions to Long-range Spin–Spin Coupling Constants in the Methyl Derivatives of the Fluoropyridines (1972) Canadian Journal of Chemistry, 50, p. 2344 M. D. Beer, Daresbury Laboratory NMR Program Library; Scuseria, Engelmann, Contreras, (1982) Theor. Chim. Acta, 61, p. 49 Bak, Christensen, Rastrup-Andersen, Tannenbaum, (1956) J. Chem. Phys., 25, p. 892 Penfold, The electron distribution in crystalline α-pyridone (1953) Acta Crystallographica, 6, p. 591 Penfold, The crystal structure of α-thiopyridone (1953) Acta Crystallographica, 6, p. 707 Hayamizu, Yamamoto, (1968) J. Mol. Spectrosc., 25, p. 422 Kowalewski, (1969) J. Mol. Spectrosc., 30, p. 531 ITRCAL program, Nicolet Users Library |
| ISSN: | 01661280 |
| DOI: | 10.1016/0166-1280(83)80168-7 |