Table of Content.- Topics in Ion Photodissociation.- 1. Introduction.- 2. Experimental Aspects.- 3. Ion Spectroscopy.- 4. Ion Structure Studies.- 4.1.Chloropropene Ions.- 4.2.Benzyl Chloride Ion.- 4.3.Dien-Ion Rearrangements.- 5. Photofragmentation.- 6. Multi photon Photochemistry.- 6.1. Two-Photon Dissociation and Collisional Relaxation.- 6.2. Two-Laser Photodissociation.- References.- Ion Structures and Relaxation of Vibrationally Excited Ions as Studied by Photodissociation.- 1. Introduction.- 1.1. Photodissociation of Ions of One Structural Form.- 1.2. Photodissociation of a Mixture of Ions of Equal Mass.- 1.3. Relaxation of Ions Produced with a Large Amount of Internal Energy.- 1.4. Multiphoton Processes.- 2. Ion Structures.- 2.1. C6H6O?+ Ions.- 2.2. Alkene Ions.- 3. Relaxation in Single Photon Precesses, C2H4?+ Ions from Ethylene Oxide and 1,3-Dioxolane.- 4. Two Photon Processes.- References.- Infrared Photochemistry of Gas Phase Ions.- 1. Introduction.- 2. Experimental Section.- 3. Results.- 3.1. Multiphoton Dissociation of Ions with Low Intensity cw Infrared Radiation.- 3.1.1. Summary of Multiphoton Dissociation Results.- 3.1.2. Variation of Photodissociation Yield with Laser Wavelength.- 3.1.3. Effect of Collisions on Photodissociation Yield.- 3.1.4. Variation of Photodissociation Yield with Laser Irradiance.- 3.2. Applications of Multiphoton Dissociation.- 3.2.1. Multiphoton Excitation as a Probe of Bimolecular and Unimolecular Reaction Energetics.- 3.2.2. Multiphoton Dissociation as a Probe of Molecular Relaxation Rates.- 3.2.3. Multiphoton Dissociation as a Probe of the Vibrational Quasi-Continuum.- 3.2.4. Isotopic Selectivity in Multiphoton Dissociation.- 3.2.5. Isomeric Selectivity in Multiphoton Dissociation.- 3.3. Multiphoton Electron Detachment from Negative Ions.- 3.4. Selective Enhancement of Bimolecular Reaction Rates Using Low Intensity cw Laser Radiation.- 4. Prognosis.- References.- Study of Atomic Metal Ions Generated by Laser Ionization.- 1.lU