Please use this identifier to cite or link to this item: http://dx.doi.org/10.18419/opus-7749
Spiess, Hans Wolfgang
|Title:||Anisotropic chemical shifts and spin rotation constants of 15N from liquid and solid state NMR: Nitrobenzene|
|metadata.ubs.publikation.source:||Journal of magnetic resonance 16 (1974), S. 243-251. URL http://dx.doi.org./10.1016/0022-2364(74)90048-1|
|Abstract:||The study of the 15N spin-lattice relaxation time T1 in nitrobenzene at 14 and 32 MHz from −10 to 60°C showed that at 32 MHz relaxation due to anisotropic chemical shift is predominant. At low frequencies, the relaxation is caused mainly by spin rotation and at low temperature also by intermolecular dipole-dipole interaction. From the powder spectrum in solid nitrobenzene, the principal elements of the shielding tensor σ were obtained: σxx = −273 ± 10 ppm, σyy = +94 ± 10 ppm, and σzz = +156 ± 10 ppm relative to liquid nitrobenzene, Δσ = σ xx - ½(σ yy + σ zz) = -398 ± 20ppm. From the almost axially symmetric σ -tensor, the spin rotation constants were calculated: C‖ = 11.4 ± 1.5 kHz and C⊥ = 1.35 ± 0.5 kHz, where C‖ is the component parallel to the twofold axis of the molecule. These values for Δσ and the spin rotation constants are in excellent agreement with those obtained by analysis of the relaxation data. A comparison of anisotropic chemical shifts and spin rotation constants for 15N and 13C in isoelectronic compounds is given.|
|Appears in Collections:||15 Fakultätsübergreifend / Sonstige Einrichtung|
Items in OPUS are protected by copyright, with all rights reserved, unless otherwise indicated.