How do we know:
• how atoms are connected together?
• Which bonds are single, double, or triple?
• What functional groups exist in the molecule?
• If we have a specific stereoisomer? The field of organic structure determination attempts to answer these questions.'
INSTRUMENTAL METHODS OF STRUCTURE DETERMINATION
1. Nuclear Magnetic Resonance (NMR) – Excitation of the nucleus of atoms through radiofrequency irradiation. Provides extensive information about molecular structure and atom connectivity.
2. Infrared Spectroscopy (IR) – Triggering molecular vibrations through irradiation with infrared light. Provides mostly information about the presence or absence of certain functional groups.
3. Mass spectrometry – Bombardment of the sample with electrons and detection of resulting molecular fragments. Provides information about molecular mass and atom connectivity.
4. Ultraviolet spectroscopy (UV) – Promotion of electrons to higher energy levels through irradiation of the molecule with ultraviolet light. Provides mostly information about the presence of conjugated π systems and the presence of double and triple bonds.