ORGANIC CHEMISTRY Chapter 9 g Nuclei with an odd mass or odd atomic number have nuclear spin"(in a similar fashion to the spin of electrons ) This includes H and 3C(but not 2C) o The nuclei of protons (h)and carbon-13(C),and certain other elements and isotopes, behave as if they were tiny bar magnets g When placed in a magnetic field and irradiated with radio frequency energy these nuclei absorb energy at frequencies based on their chemical environments o nmr spectrometers are used to measure these absorptions Department of Chemistry, Xiamen UniversityORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9 Nuclei with an odd mass or odd atomic number have "nuclear spin" (in a similar fashion to the spin of electrons). This includes 1H and 13C (but not 12C). The nuclei of protons (1H) and carbon-13 (13C), and certain other elements and isotopes, behave as if they were tiny bar magnets When placed in a magnetic field and irradiated with radio frequency energy, these nuclei absorb energy at frequencies based on their chemical environments NMR spectrometers are used to measure these absorptions