The Contact-term Contributions to Lanthanide-induced 13C Paramagnetic Shifts in Acridine, Quinoline, and Isoquinoline

1H and 13C paramagnetic shifts induced by Eu(DPM)3 and Pr(DPM)3 in acridine, quinoline, and isoquinoline in CCl4 are observed. It has been found that, while the 1H shifts can be interpreted solely in terms of a pseudo-contact interaction, there is a much larger contact-term contribution to 13C shifts induced by Eu(DPM)3 than by Pr(DPM)3 in these compounds; this contribution to the 13C shifts cannot be explained by a simple combination of σ- and π-contact terms.

[1]  T. Shepherd,et al.  Lanthanide induced paramagnetic shifts—derivation of equilibrium constants and absolute shifts in Eu(DPM)3 systems , 1972 .

[2]  J. Reuben,et al.  Effects of paramagnetic lanthanide shift reagents on the proton magnetic resonance spectra of quinoline and pyridine , 1972 .

[3]  I. Morishima,et al.  Nuclear magnetic resonance contact shifts and electron spin distribution. Proton and carbon-13 contact-shift studies of azanaphthalenes , 1972 .

[4]  W. Horrocks,et al.  Lanthanide shift reagents. Survey , 1971 .

[5]  W. Horrocks,et al.  Lanthanide shift reagents. X-ray structure of the eight-coordinate bis(4-picoline) adduct of 2,2,6,6-tetramethylheptane-3,5-dionatoholmium, Ho(dpm)3(4-pic)2 , 1971 .

[6]  C. Pascual,et al.  Über den Einfluss des Kontaktterms auf die Lantlianiden‐Verschiebung der NMR.‐Signale aromatischer stickstoffheterocyclen , 1971 .

[7]  E. R. Birnbaum,et al.  Observations on the rare earths. LXXXII. Nuclear magnetic resonance and calorimetric studies of complexes of the tripositive ions with substituted pyridine molecules , 1969 .

[8]  R. K. Robins,et al.  Carbon-13 magnetic resonance. XIV. Aza-analogs of polycyclic aromatic hydrocarbons , 1969 .

[9]  C. C. Hinckley.  Paramagnetic shifts in solutions of cholesterol and the dipyridine adduct of trisdipivalomethanatoeuropium. 3. A shift reagent. , 1969, Journal of the American Chemical Society.

[10]  L. C. Allen,et al.  Isotropic Proton Resonance Shifts of Some Bis‐(triarylphosphine) Complexes of Cobalt(II) and Nickel(II) Dihalides , 1964 .

[11]  F. Fehsenfeld.  Cyclotron Resonance in Slightly Ionized Gases , 1963 .

[12]  M. Karplus,et al.  THEORETICAL INTERPRETATION OF CARBON-13 HYPERFINE INTERACTIONS IN ELECTRON SPIN RESONANCE SPECTRA. Technical Note Report No. 9 , 1961 .

[13]  A. D. McLachlan,et al.  Self-consistent field theory of the electron spin distribution in π-electron radicals , 1960 .