Protons, 13 C and 31 P are all spin half nuclei. Note that the most common isotope of carbon, 12 C, has no spin and can therefore not be observed using NMR. Nuclei with a non-spherical charge distribution have a spin number I of 1, 3/2 or higher (in steps of ½ ), and are referred to as quadrupolar nuclei. Spin ½ nuclei have two orientations ... Nuclear Magnetic Resonance Spectroscopy, or NMR Spectroscopy, can be used to identify any isotope unless 1H NMR Spectroscopy (proton nuclear magnetic resonance spectroscopy) is used to identify the structure How many signals are predicted to be in the 1H NMR spectrum of ethanol?
Fig. 4-2.12 The Proton-decoupled 13C NMR spectrum of toluene. A symmetrically disubstituted Fig. 4-2.13 The Proton-decoupled 13C NMR spectra of the three isomers of 1,2-dichlorobenzene Polysubstitution Most other polysubstitution patterns on a benzene ring yield six different peaks.