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Foundations of Photochemistry: A Background on the Interaction Between Light and Molecules

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Applied Photochemistry

Abstract

This chapter gives an introduction to the key ideas which underpin photochemistry: the nature of electromagnetic radiation, the nature of matter, and the way the two interact. After a discussion of ultraviolet and visible electromagnetic radiation and its interaction with the optical properties of materials, an account is given of the fundamental properties of the four components involved in photochemistry, the protons, neutrons and electrons which make up atoms, and the photon. The ideas of wave mechanics and its application to atomic structure are introduced in a non-mathematical way, with atomic orbitals described in terms of quantum numbers, energies, degeneracies, shapes and symmetries. The role of electron spin in governing orbital occupancy is discussed, along with the structure of many-electron atoms and the use of term symbols to identify the various spin, orbital, and total angular momenta of atomic states. The use of atomic orbitals as constructs for molecular orbitals and molecular bonding is described. Term symbols for small molecules are illustrated briefly using O2, which is particularly important in photochemistry, as an example. The concepts of a Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) are introduced, and the importance of these orbitals in photochemistry is explained. Bonding in conjugated systems, metals and semiconductors is described. The link between energy levels and electrochemical redox potentials is made. The various energy states in atoms molecules and solids, and the way energy is distributed within these energy levels according to the Boltzmann equation, are described. Timescales for various physical and photochemical processes are given. The interaction of electronic energy states with ultraviolet and visible light is discussed in terms of absorption, emission and stimulated emission, using the Einstein A and B coefficients, transition probabilities, and absorption coefficients. The absorption process and the various selection rules which control the efficiency of absorption, and emission, are described, as are the common types of electronic transitions. Absorption in gas, solution, and solid phases, and the effect of aggregation on absorption in solution, are discussed. Unimolecular radiative and non-radiative excited state deactivation processes are discussed in terms of the Jablonski diagram, and the ideas of, competition between decay routes, and quantum yield, are introduced. Bimolecular interactions, quenching and energy transfer are described, with Förster Resonance Energy Transfer (FRET) and Dexter energy transfer discussed in some detail, and the analysis of bimolecular quenching kinetics using the Stern–Volmer equation is given. The chapter finishes with brief discussions of excimers, exciplexes, delayed fluorescence and proton transfer.

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References

  1. Braslavsky SE (2007) Glossary of terms used in photochemistry 3rd edition (IUPAC recommendations 2006). Pure Appl Chem 79:293–465

    Article  CAS  Google Scholar 

  2. http://www.lsbu.ac.uk/water/vibrat.html. Accessed 8 Sept 2012

  3. Elsaesser T, Kaiser W (1991) Vibrational and vibronic relaxation of large polyatomic molecules in liquids. Ann Rev Phys Chem 42:83–107

    Article  CAS  Google Scholar 

  4. Hodgman SS, Dall RG, Byron LJ, Baldwin KGH, Buckman SJ, Truscott AG et al (2009) Metastable helium: a new determination of the longest atomic excited-state lifetime. Phys Rev Lett 103:053002

    Article  CAS  Google Scholar 

  5. Newman SM, Lane IC, Orr-Ewing AJ, Newnam DA, Ballard J et al (1999) Integrated absorption intensity and Einstien coefficients for the O2 a 1Δg- X 3Σg-(0,0) transition: A comparison of cavity ringdown and high resolution Fourier transform spectroscopy with a long-path absorption cell. J Chem Phys 110:10749–10757

    Article  CAS  Google Scholar 

  6. Atkins P, de Paula J, Friedman R (2009) Quanta, matter and change: a molecular approach to physical chemistry. Oxford University Press, Oxford

    Google Scholar 

  7. Dorn R, Quabis S, Leuchs G (2003) Sharper focus for a radially polarized light beam. Phys Rev Lett 91:233901–233904

    Article  CAS  Google Scholar 

  8. The photonics dictionary (2009) Book 4, 45th edn. Laurin Publishing Co, Pittsfield

    Google Scholar 

  9. Smith FG, King TA (2000) Optics and photonics. An introduction. John Wiley, Chichester

    Google Scholar 

  10. Michelson AA, Morley EW (1887) On the relative motion of the earth and the luminiferous ether. Am J Sci 34:333–345

    Google Scholar 

  11. Hell SW (2007) Far-field optical nanoscopy. Science 316:1153–1158

    Google Scholar 

  12. Moore WJ et al(1972) Physical chemistry. Longman, London

    Google Scholar 

  13. Moore AD (ed) (1983) Electrostatics and its applications. John Wiley, New York Chapter 1

    Google Scholar 

  14. Banwell C, McCash E (1994) Fundamentals of molecular spectroscopy, 4th edn. Mcgraw-Hill

    Google Scholar 

  15. Hollas JM (2004) Modern spectroscopy, 4th edn. Wiley, Chichester

    Google Scholar 

  16. Worner HJ, Niikura H, Bertrand JB, Corkum PB,Villeneuve DM (2009) Observation of electronic structure minima in high-harmonic generation. Phys Rev Lett 102:103901

    Google Scholar 

  17. Housecroft CE, Sharpe AG (2001) Inorganic chemistry. Prentice Hall, Harlow, pp 16–25

    Google Scholar 

  18. Pritchard HO (2012) We need to update the teaching of valence theory. J Chem Ed 89:301–303

    Article  CAS  Google Scholar 

  19. Sandorfy C (1964) Electronic spectra and quantum chemistry. Prentice-Hall, Englewood Cliffs

    Google Scholar 

  20. Harris DC, Bertolucci MD (1989) Symmetry and spectroscopy: an introduction to vibrational and electronic spectroscopy. Dover, New York

    Google Scholar 

  21. Campbell MK (1980) The 1A1g → 1B2u transition of benzene. J Chem Ed 57:756–758

    Article  CAS  Google Scholar 

  22. Pope M, Swenberg CE (1999) Electronic processes in organic crystals and polymers. Oxford University Press, Oxford

    Google Scholar 

  23. Davydov AS (1971) Theory of molecular excitons. Plenum, New York

    Google Scholar 

  24. Kasha M, Rawls HR, El-Bayoumi MA (1965) The exciton model in molecular spectroscopy. Pure Appl Chem 11:371–392

    Article  CAS  Google Scholar 

  25. Guerrero AH, Fasoli HJ, Costa JL (1999) Why gold and copper are coloured but silver is not. J Chem Ed 76:200

    Article  CAS  Google Scholar 

  26. Heeger AJ, Kivelson S, Schrieffer JR, Su WP (1988) Solitons in conducting polymers. Rev Mod Phys 60:781–850

    Article  CAS  Google Scholar 

  27. Rauscher U, Bässler H, Bradley DDC, Hennecke M (1990) Exciton versus band description of the absorption and luminescence spectra in poly(p-phenylenevinylene). Phys Rev B 42:9830–9836

    Article  CAS  Google Scholar 

  28. Sariciftci NS (ed) (1998) Primary photoexcitations in conjugated polymers: molecular exciton versus semiconductor band model. World Scientific, Singapore

    Google Scholar 

  29. Schweitzer B, Bässler H (2000) Excitons in conjugated polymers. Synth Met 109:1–6

    Article  CAS  Google Scholar 

  30. Köhler A, Bässler H (2011) What controls triplet exciton transfer in organic semiconductors? J Mater Chem 21:4003–4011

    Article  Google Scholar 

  31. Schwartz BJ (2003) Conjugated polymers as molecular materials: How chain conformation and film morphology influence energy transfer and interchain interactions. Ann Rev Phys Chem 54:141–172

    Article  CAS  Google Scholar 

  32. Ebsworth EAV, Rankin DWH, Cradock S (1991) Structural methods in inorganic chemistry, 2nd edn. Blackwell Scientific Publications, Oxford

    Google Scholar 

  33. Moore CE (1970) Analyses of optical spectra. Office of Standard Reference Data, NSRDS-NBS 34. National Bureau of Standards. Washington, DC

    Google Scholar 

  34. Montalti M, Credi A, Prodi L, Gandolfi MT (2006) Handbook of photochemistry, 3rd edn. CRC Press, Boca Raton

    Google Scholar 

  35. Trasetti S (1986) The absolute electrode potential—an explanatory note. Pure Appl Chem 58:955–966

    Article  Google Scholar 

  36. Brett CMA, Brett AMO (1993) Electrochemistry: principles, methods, and applications. Oxford University Press, Oxford

    Google Scholar 

  37. Connelly NG, Geiger WE (1996) Chemical redox agents for organometallic chemistry. Chem Rev 96:877–910

    Article  CAS  Google Scholar 

  38. Cardona CM, Li W, Kaifer AE, Stockdale D, Bazan GC et al (2011) Electrochemical considerations for determining absolute frontier orbital energy levels of conjugated polymers for solar cell applications. Adv Mater 23:2367–2371

    Article  CAS  Google Scholar 

  39. Kalyanasundaram K (1982) Photophysics, photochemistry and solar energy conversion with tris(bipyridyl)ruthenium(II) and its analogues. Coord Chem Rev 46:159–244

    Article  CAS  Google Scholar 

  40. Burrows HD, Azenha ME, Monteiro CJP (2008) Homogeneous photocatalysis. In: Figueiredo JL, Pereira MM, Faria J (eds) Catalysis from theory to application. Coimbra University Press, Coimbra

    Google Scholar 

  41. Koopman T (1934) Über die Zuordnung von Wellenfunktionen und Eigenwerten zu den einzelnen Elektronen eines Atoms. Physica 1:104–113

    Article  Google Scholar 

  42. Ramsey BG (1977) A comparison of the role of charge transfer hyperconjugation, inductive and field interactions in substituted methyl and silyl substituent effects in benzene π vertical ionization energies. J Organomet Chem 135:307–319

    Article  CAS  Google Scholar 

  43. Doering JP (1977) Electronic energy levels of benzene below 7 eV. J Chem Phys 67:4065–4070

    Article  CAS  Google Scholar 

  44. Palmer MH, Walker IC (1989) The electronic states of benzene and the azines. 1 The parent compound benzene. Correlation of vacuum UV and electron scattering data with ab initio calculations. Chem Phys 133:113–121

    Article  CAS  Google Scholar 

  45. Orchin M, Jaffe HH (1971) Symmetry, orbitals and spectra. Wiley, New York

    Google Scholar 

  46. Wayne RP (1988) Principles and applications of photochemistry. Oxford University Press, Oxford

    Google Scholar 

  47. Sturm JE (1990) Grid of expressions related to the Einstein coefficients. J Chem Ed 67:32–33

    Article  CAS  Google Scholar 

  48. Benessi HA, Hildebrand JH (1949) A spectrophotometric investigation of the interaction of iodine with aromatic hydrocarbons. J Am Chem Soc 71:2703–2707

    Article  Google Scholar 

  49. Kasha M (1963) Energy transfer mechanisms and the molecular exciton model for molecular aggregation. Radiat Res 20:55–71

    Article  CAS  Google Scholar 

  50. Jelley EE (1936) Spectral absorbance and fluorescence of dyes in the molecular state. Nature 138:1009–1010

    Article  CAS  Google Scholar 

  51. Scheibe G (1937) Über die Veränderlichkeit der Absorptionsspektren in Lösungen und die Nebenvalenzen als ihre Ursache. Angew Chem 50:212–219

    Article  CAS  Google Scholar 

  52. Würthner F, Kaiser TE, Saha-Möller CR (2011) J-aggregates: from serendipitious discovery to supramolecular engineering of functional dye molecules. Angew Chem Int Ed 50:3376–3410

    Article  Google Scholar 

  53. Tilley R (2011) Colour and the optical properties of materials, 2nd edn. Wiley, Chichester

    Google Scholar 

  54. Prasad PN, Williams DJ (1990) Introduction to nonlinear optical effects in molecules and polymers. Wiley, New York

    Google Scholar 

  55. Strickler SJ, Berg RA (1962) Relationship between absorption intensity and fluorescence lifetime of molecules. J Chem Phys 37:814–822

    Article  CAS  Google Scholar 

  56. Kasha M (1950) Characterization of electronic transitions in complex molecules. Disc Faraday Soc 9:4–19

    Article  Google Scholar 

  57. Cario G, Franck J (1923) On sensitized fluorescence of gases. Z Phys 17:202–212

    Article  CAS  Google Scholar 

  58. Förster T (1948) Zwischenmolekulare energiewanderung und fluoreszenz. Ann Phys 2:55–75

    Google Scholar 

  59. Förster T (1959) Transfer mechanisms of electronic excitation. Disc Faraday Soc 27:7–17

    Article  Google Scholar 

  60. Berlman IB (1973) Energy transfer parameters of aromatic compounds. Academic Press, New York

    Google Scholar 

  61. Arnaut L, Formosinho S, Burrows H (2007) Chemical kinetics: from molecular structures to chemical reactivity. Elsevier, Amsterdam, pp 229–235

    Google Scholar 

  62. Marcus RA, Sutin N (1985) Electron transfers in chemistry and biology. Biochim Biophys Acta 811:265–322

    Google Scholar 

  63. Piotrowiak P (2001) Relationship between electron and electronic excitation transfer. In: Balzani V (ed) Electron transfer in chemistry, vol 1. Wiley-VCH, Weinheim

    Google Scholar 

  64. Dexter DL (1953) A theory of sensitized luminescence in solids. J Chem Phys 21:836–850

    Article  CAS  Google Scholar 

  65. Saini S, Srivinivas G, Bagchi M (2009) Distance and orientation dependence of excitation energy transfer: From molecular systems to metal nanoparticles. J Phys Chem B 113:1817–1832

    Google Scholar 

  66. Hwang I, Scholes GD (2011) Electronic energy transfer and quantum-coherence in π-conjugated polymers. Chem Mater 23:610–620

    Google Scholar 

  67. Stern O, Volmer M (1919) Über die Abklingzeit der Fluoreszenz. Physikalische Zeitschrift 20:183–188

    CAS  Google Scholar 

  68. Förster T, Kasper K (1954) Ein Konzentrationsumschlag der Fluoreszenz. Z Phys Chem Neue Folge 1:275–277

    Article  Google Scholar 

  69. Stevens B, Hutton E (1960) Radiative lifetime of the pyrene dimer and possible role of excited dimers in energy transfer processes. Nature 186:1045–1046

    Article  CAS  Google Scholar 

  70. Birks JB (1970) Excimer fluorescence of aromatic compounds. Prog React Kinetics 5:181–272

    CAS  Google Scholar 

  71. Hopfield JJ (1930) Absorption and emission spectra in the region λ = 600–1100. Phys Rev 35:1133–1134

    Article  CAS  Google Scholar 

  72. Leonhardt H, Weller A (1963) Elektronenübertragungsreaktionen des angeregten Perylens. Ber Buns Phys Chem 67:791–795

    CAS  Google Scholar 

  73. Knibb H, Rehm D, Weller A (1968) Intermediates and kinetics of fluorescence quenching by electron transfer. Ber Buns Phys Chem 72:257–263

    Google Scholar 

  74. Mataga N, Chosrojan H, Taniguchi S (2005) Ultrafast charge transfer in excited electronic states and investigation into fundamental problems of exciplex chemistry: our early studies and recent developments. J Photochem Photobiol C 6:37–79

    Article  CAS  Google Scholar 

  75. Grabowski ZR, Dobkowski J (1983) Twisted intramolecular charge transfer (TICT) excited states: energy and molecular structure. Pure Appl Chem 55:245–252

    Article  CAS  Google Scholar 

  76. Parker CA (1964) Phosphorescence and delayed fluorescence from solutions. Adv Photochem 2:305–383

    Article  Google Scholar 

  77. Berberan Santos MN, Garcia JMM (1996) Unusually strong delayed fluorescence of C70. J Am Chem Soc 118:9391–9394

    Article  CAS  Google Scholar 

  78. Birks JB (1967) Quintet state of pyrene excimer. Phys Lett A 24:479

    Article  CAS  Google Scholar 

  79. Misra TN (1973) Delayed fluorescence of organic mixed crystals—temperature independent delayed fluorescence in biphenyl host. J Chem Phys 58:1235–1242

    Article  CAS  Google Scholar 

  80. Monkman A, Rothe C, King S, Dias F (2008) Polyfluorene photophysics. Adv Polym Sci 212:187–225

    Google Scholar 

  81. Monkman AP, Burrows HD, Hamblett I, Navaratnam S (2001) Intrachain triplet–triplet annihilation and delayed fluorescence in soluble conjugated polymers. Chem Phys Lett 340:467–472

    Article  CAS  Google Scholar 

  82. Förster TH (1950) Die pH Abhägigkeit der Fluoreszenz von Naphthalinderivaten. Z Elelectrochem 54:531–535

    Google Scholar 

  83. Ireland JF, Wyatt PAH (1976) Acid-base properties of electronically excited states of organic molecules. Adv Photochem 12:131–221

    CAS  Google Scholar 

  84. Weller A (1961) Fast reactions of excited molecules. Prog React Kinet 1:187–214

    CAS  Google Scholar 

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Douglas, P., Burrows, H.D., Evans, R.C. (2013). Foundations of Photochemistry: A Background on the Interaction Between Light and Molecules. In: Evans, R., Douglas, P., Burrow, H. (eds) Applied Photochemistry. Springer, Dordrecht. https://doi.org/10.1007/978-90-481-3830-2_1

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