§10.6 Photochemistry 6.2 Physical processes of Excitation and decay (1)Photoexcitation: Efficiency of Anti-Stokes Fluorescence in Dyes AccoRDING to Kautsky and his collaborators, the majority of the molecul les of dyos investigated by them, anong which were also the molecules of fluoresceine, show an ability to phosphoresce when energetically isolated,, for example, when adsorbed by convenient adsorbents e can assume therefore Va M vvvv 3210 N vels in phorescent molecule on to metastable lev( The Foundation of a typical Jablonski diagram nall transition probabil scence, g-absorption of A Jablonski, Efficient of Anti-Stokes Fluorescence in Dyes Nature,1933,Jun.10,839-840
The Foundation of a typical Jablonski Diagram (1) Photoexcitation: 6.2 Physical processes of Excitation and decay §10. 6 Photochemistry A. Jablonski, Efficient of Anti-Stokes Fluorescence in Dyes, Nature, 1933, Jun. 10, 839-840
§10.6 Photochemistry 6.2 Physical processes of Excitation and decay (1)Photoexcitation Internal conversion Absorbance Vibrational relaxation and Internal Conversion 2 Insystem conversion Intersystem Crossing Fluorescence absorption I T Phosphorescence i/ fluorescence v absorption 光子光激发基态激发态能级能带雅布 phosphorescence 隆斯基( Jablonski)图激发态衰变振动弛 豫内转换系间穿越辐射跃迁无辐射跃迁 rotational vibration state 单线态三线态荧光磷光 state 0 ground state Jablonski diagram
Jablonski diagram 6.2 Physical processes of Excitation and decay (1) Photoexcitation: §10. 6 Photochemistry Absorbance Vibrational Relaxation and Internal Conversion Intersystem Crossing Fluorescence Phosphorescence 光子 光激发 基态 激发态 能级 能带 雅布 隆斯基（Jablonski）图 激发态衰变 振动弛 豫 内转换 系间穿越 辐射跃迁 无辐射跃迁 单线态 三线态 荧光 磷光
§10.6 Photochemistry 6.2 Physical processes of Excitation and decay (1)Photoexcitation Radiation-less decay Which is which? radiation v fluorescence ground state singlet ground state radiation 八八、 phosphorescence 4005006007008009001000 Wavelength(nm) ground state 大
Radiation-less decay Which is which? 6.2 Physical processes of Excitation and decay (1) Photoexcitation: §10. 6 Photochemistry
§10.6 Photochemistry 6.2 Physical processes of Excitation and decay (1)Photoexcitation Transition Time Scale Radiative Process? Internal Conversion 10 -14 10 no 14 Vibrational relaxation 10 -10s no 15 Absorption 10s yes Phosphorescence 10-10s yes Intersystem Crossing 10°10s no Fluorescence 10-10s yes https://chem.libretexts.org/textbook_maps/physical_andtheoreticAlChemistryTextbook_maps/suppl emental_ Modules_(Physical and_ Theoretical_ Chemistry)/Spectroscopy/Electronic_ Spectroscopy/Jablo ski diagram
Transition Time Scale Radiative Process? Internal Conversion 10-14 - 10-11 s no Vibrational Relaxation 10-14 - 10-11 s no Absorption 10-15 s yes Phosphorescence 10-4 - 10-1 s yes Intersystem Crossing 10-8 - 10-3 s no Fluorescence 10-9 - 10-7 s yes 6.2 Physical processes of Excitation and decay (1) Photoexcitation: §10. 6 Photochemistry https://chem.libretexts.org/Textbook_Maps/Physical_and_Theoretical_Chemistry_Textbook_Maps/Suppl emental_Modules_(Physical_and_Theoretical_Chemistry)/Spectroscopy/Electronic_Spectroscopy/Jablo nski_diagram
§10.6 Photochemistry 6.2 Physical processes of Excitation and decay (2) Decay of photoexcited molecules Radiation transition Fluorescence and phosphorescence non-reactive decay Radiationless Vibrational cascade and thermal transition energy decay Reaction of excited molecule A"→P reactive deca Energy transfer A+Q→>Q→P
(2) Decay of photoexcited molecules decay non-reactive decay reactive decay Radiation transition Radiationless transition Fluorescence and phosphorescence Vibrational cascade and thermal energy Reaction of excited molecule A* → P Energy transfer: A* + Q → Q* → P 6.2 Physical processes of Excitation and decay §10. 6 Photochemistry