Photochemistry and Photophysics

30 lessons, pages 4311–4340.

  1. Photochemistry: From Photon to Product — Separating light absorption, excited-state motion and chemical reaction
  2. Electronic Excited States — Vertical excitation, potential-energy surfaces and Franck–Condon reasoning
  3. The Jablonski Diagram — Absorption, fluorescence, phosphorescence and radiationless transitions
  4. Singlet and Triplet States — Spin multiplicity, intersystem crossing and lifetime differences
  5. Fluorescence Spectra and Stokes Shift — Relaxation before emission and the relation between absorption and emission bands
  6. Phosphorescence and Spin–Orbit Coupling — Triplet emission, heavy-atom effects and competing nonradiative loss
  7. Excited-State Lifetimes — Radiative and nonradiative rate constants in population decay
  8. Quantum Yield — Defining photons absorbed and events produced for emission or chemical transformation
  9. Measuring Photochemical Quantum Yields — Actinometry, absorbed-light correction and uncertainty
  10. Stern–Volmer Quenching — Dynamic and static quenching with intensity and lifetime tests
  11. Energy Transfer Between Molecules — Förster and Dexter mechanisms and distance dependence
  12. Photoinduced Electron Transfer — Excited-state redox potentials and charge-separated intermediates
  13. Excited-State Acid–Base Chemistry — How excitation can change proton affinity and reaction pathways
  14. Photochemical Reaction Coordinates — Excited-state minima, crossings and nonadiabatic product channels
  15. Conical Intersections in Photochemistry — Ultrafast internal conversion at electronic-state intersections
  16. Photochemical Isomerization — Geometry change, bond rotation and competing excited-state relaxation
  17. Photocycloadditions — Light-enabled bond formation and the role of excited electronic symmetry
  18. Photocleavage and Radical Formation — Homolysis, cage effects and product selectivity
  19. Photosensitization — Antenna absorption followed by energy or electron transfer to a substrate
  20. Photoredox Catalysis — Oxidative and reductive quenching cycles with electron-balance checks
  21. Photocatalytic Water Splitting — Light absorption, charge separation, cocatalysts and overall redox balance
  22. Semiconductor Photocatalysts — Band-edge positions, carriers, defects and surface reaction kinetics
  23. Solar-Fuel Selectivity — Competition among proton, oxygen and carbon-dioxide reduction pathways
  24. Photodegradation and Photostability — Reactive excited states, oxygen effects and materials aging
  25. Time-Resolved Spectroscopy — Pump–probe and transient-emission measurements of excited-state populations
  26. Ultrafast Dynamics — Femtosecond relaxation, coherent motion and limits of simple kinetic schemes
  27. Light Intensity and Photochemical Rates — Photon flux, inner-filter effects and saturation behavior
  28. Photoreactor Design — Optical path, mixing, absorption profile and scale-up limitations
  29. Responsible Photochemical Measurement — Reporting wavelengths, spectrum, power, absorption and product analysis
  30. Photochemistry and Photophysics: Unit Review — Connecting excited-state pathways, measurements and light-driven reactions