ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The 15N/14N isotope shift on the 15N chemical shielding in a mixture of 15N14N and 15N15N was found to be 0.0601±0.0022 ppm. Using a model developed by Jameson, the nuclear shielding derivative with respect to bond length was calculated from the measured isotope shift, [∂σ(15N)/∂r]e =−910±42 ppm/A(ring). This value is in excellent agreement with a value obtained from the temperature dependence of the shielding constant in the gas phase (at the zero pressure limit) and with a value determined from recent molecular orbital calculations. From relaxation measurements the scalar spin–spin coupling constant, 1J(14N,15N), in 14N15N was calculated to be 1.8±0.6 Hz which gives a reduced coupling constant, 1K(N,N)=2.0±0.7 (1020)m−2kg s−2 A(ring)−2. The magnitude of the reduced coupling constant is compared to that of other isoelectronic species and molecular orbital calculations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.449128
