Spin Properties of Nuclei

Nuclear spin may be related to the nucleon composition of a nucleus in the following manner:
      Odd mass nuclei (i.e. those having an odd number of nucleons) have fractional spins. Examples are I = 1/2 ( ¹H, ¹³C, ¹⁹F ), I = 3/2 ( ¹¹B ) & I = 5/2 ( ¹⁷O ).
      Even mass nuclei composed of odd numbers of protons and neutrons have integral spins. Examples are I = 1 ( ²H, ¹⁴N ).
      Even mass nuclei composed of even numbers of protons and neutrons have zero spin ( I = 0 ). Examples are ¹²C, and ¹⁶O.
Spin 1/2 nuclei have a spherical charge distribution, and their nmr behavior is the easiest to understand. Other spin nuclei have nonspherical charge distributions and may be analyzed as prolate or oblate spinning bodies. All nuclei with non-zero spins have magnetic moments (μ), but the nonspherical nuclei also have an electric quadrupole moment (eQ). Some characteristic properties of selected nuclei are given in the following table.

* μ in units of nuclear magnetons = 5.05078•10^-27 JT^-1
† γ in units of 10⁷rad T^-1 sec^-1

مواضيع ذات صلة

Spectroscopic Properties of Alkynes

Spectroscopic Properties of Alkenes

Application of Chemical Shifts to Structure Determination

Correlations Between Structure and Chemical Shifts

Electronegativity and Chemical Shifts

Effects of Carbon Bond Type

Mass Spectroscopy

Hydrogen Bonding

Chemical Exchange

Proton-Proton Splittings and Conformational Analysis

Spin-Spin Splitting - What We Observe

Proton-Proton Splittings and Chemical Exchange