STM Journals Peer-reviewed research from Consortium e-Learning Network

International Journal of Photochemistry and Photochemical Research Review Article

Light-Matter Interactions in Molecular Photochemistry

  1. Sandeep Rai Department of Chemistry, UPL University of Sustainable Technology, Vataria, Ankleshwar, Bharuch

Abstract

Molecular photochemistry explores the ways of molecules interaction with light, absorb photons, and excited‐state processes, and ultimately conversion of photon energy into chemical change. Core concepts of this innovative and relevant field are matter interaction like electronic, vibrational, and rotational transitions; non‐adiabatic couplings; energy & electron transfer; and light–matter coupling in weak and strong regimes. This article briefly surveys the multiplicity of these interactions, from the fundamentals of photon absorption & excitation, through pathways of excited‐state relaxation, to emerging effects caused by the interaction of molecules with quantized electromagnetic fieldsin cavities or under strong coupling. It explores classic mechanisms such as Förster and Dexter energy transfer, intersystem crossing, internal conversion, photo isomerization, photo dissociation, and the role of conical intersections and non‐Born–Oppenheimer behaviour. Theoretical frameworks, including quantum electrodynamics [QED], non‐adiabatic molecular dynamics, and ab initio approaches, are discussed to provide insight to understand how matter interactions can be modelled and controlled. Recent advances such as polariton chemistry, where hybrid light‐matter states [polaritons] alter potential energy surfaces and influence reaction pathways, are discussed. The influence of environment [solvent, matrix, intermolecular interactions] and external controls [cavity design, photon mode frequency, coupling strength, polarization] are highlighted. The article also briefly covers experimental techniques developed to precisely observe these interactions—spectroscopy [steady‐state, time‐ resolved], ultrafast dynamics, transient absorption, and cavity quantum optical setups. Lastly article reports current challenges and potential future development directions i.e. controlling reaction selectivity through light–matter coupling, exploiting collective effects, integrating theory and experiment to better understand these complex systems, and possibility of applying these insights to emerging areas likes solar energy conversion, new and novel photo catalysis, molecular optoelectronics, and quantum technologies. The interactions between light and molecular matter are not simply as passive theoretical processes, but also new concepts can be designed and tune for reshaping of chemistry itself.

Keywords

References (34)

  1. George C, Brüggemann M, Hayeck N, Tinel L, Donaldson J. Interfacial Photochemistry. Physical Chemistry of Gas-Liquid Interfaces. 2018:435-457. doi:10.1016/b978-0-12-813641-6.00014-5
  2. https://microbiozindia.com/the-fundamentals-of-photochemistry-understanding-the-basics/
  3. McLaughlin R, Glennon JD. Analytical Methods | Spectroscopy, Overview. Encyclopedia of Dairy Sciences. 2011:109-114. doi:10.1016/b978-0-12-374407-4.00010-8
  4. https://journals.aps.org/prb/abstract/10.1103/PhysRevB.73.241406
  5. Band YB, Avishai Y. Angular Momentum and Spherical Symmetry. Quantum Mechanics with Applications to Nanotechnology and Information Science. 2013:105-157. doi:10.1016/b978-0-444-53786-7.00003-4
  6. Introduction: Theoretical Modelling of Excited State Processes, Spiridoula Matsika and Anna I. Krylov, Chemical Reviews, Vol. 118, Issue. 15, 2018.
  7. https://www.sciencedirect.com/topics/earth-and-planetary-sciences/internal-conversion
  8. https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.201705854#
  9. https://pubs.acs.org/doi/abs/10.1021/ed100182h
  10. Traeger JC. Photoionization and Photodissociation Methods in Mass Spectrometry. Encyclopedia of Spectroscopy and Spectrometry. 1999:1840-1847. doi:10.1006/rwsp.2000.0239
  11. Iyer ESS. The role of excited states in deciphering molecules and materials: time-resolved electronic spectroscopic studies. Molecular and Laser Spectroscopy. 2020:521-562. doi:10.1016/b978-0-12-818870-5.00015-0
  12. Klepárník K, Foret F. Recent advances in the development of single cell analysis—A review. Analytica Chimica Acta. 2013;800:12-21. doi:10.1016/j.aca.2013.09.004
  13. Skourtis SS, Liu C, Antoniou P, Virshup AM, Beratan DN. Dexter energy transfer pathways. Proceedings of the National Academy of Sciences. 2016;113(29):8115-8120. doi:10.1073/pnas.1517189113
  14. https://pubs.rsc.org/en/content/articlehtml/2023/cs/d1cs01097b#:~:text=Photoinduced%20electron%20transfer%20[PeT]%2C,signal%2Dto%2Dnoise%20ratios.
  15. Burland DM, Robinson GW. Is the Breakdown of the Born-Oppenheimer Approximation Responsible for Internal Conversion in Large Molecules? Proceedings of the National Academy of Sciences. 1970;66(2):257-264. doi:10.1073/pnas.66.2.257
  16. https://pubs.acs.org/doi/10.1021/jp003731u
  17. https://pubs.acs.org/doi/10.1021/cr9800816#:~:text=This%20technique%20provides%20detailed%20information,with%20thermally%20irreversible%20photochromic%20properties.
  18. https://testbook.com/chemistry/photochemical-reaction
  19. The coupling methods. Multiphysics Modeling. 2016:125-156. doi:10.1016/b978-0-12-407709-6.00003-1
  20. https://www.mdpi.com/20763417/12/18/9238#:~:text=In%20practice%2C%20perfectly%20lossless%20cavities,high%2Dfinesse%20cavities%20are%20required.
  21. Litinskaya M. Polaritons. Encyclopedia of Condensed Matter Physics. 2005:334-341. doi:10.1016/b0-12-369401-9/00663-x
  22. https://www.science.org/doi/10.1126/science.ade7147#:~:text=Chemical%20control%20without%20lasers%20has,8%E2%80%9310%2C%2019]
  23. https://pubs.acs.org/doi/10.1021/acs.jpca.3c01421
  24. https://journals.aps.org/pra/abstract/10.1103/PhysRevA.108.042219
  25. Brawley ZT, Pannir-Sivajothi S, Yim JE, Poh YR, Yuen-Zhou J, Sheldon M. Vibrational weak and strong coupling modify a chemical reaction via cavity-mediated radiative energy transfer. Nature Chemistry. 2025;17(3):439-447. doi:10.1038/s41557-024-01723-6
  26. https://jseepublisher.com/wp-content/uploads/19-JSEE2228.pdf#:~:text=Post%2DHartree%2DFock%20methods%2C%20such%20as%20configuration%20interaction%20[CI],account%20for%20electron%20correlation%20effects%20more%20accurately.
  27. https://journals.aps.org/prb/abstract/10.1103/PhysRevB.99.224303#:~:text=INTRODUCTION,electron%20states%20solved%20by%20TDSE.
  28. https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.053712#:~:text=Abstract,by%20conventional%20cavity%20QED%20parameters.
  29. https://journals.aps.org/pra/abstract/10.1103/PhysRevA.77.032117#:~:text=I.,interaction%20between%20system%20and%20environment.
  30. Darabi R, Azinpour E, Reis A, de Sa JC. Multi-scale Multi-physics Phase-field coupled Thermo-mechanical approach for modeling of powder bed fusion process. Applied Mathematical Modelling. 2023;122:572-597. doi:10.1016/j.apm.2023.06.021
  31. https://pubs.acs.org/doi/10.1021/jp992505l#:~:text=The%20system%20would%20appear%20homogeneous%2C%20but%20fluctuating.,to%20be%20inhomogeneous%20and%20fluctuating.
  32. https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.18.044066#:~:text=Abstract,the%20relevant%20telecom%2Dwavelength%20regime.
  33. Zhao Z, Kravtsov V, Wang Z, Zhou Z, Dou L, Huang D, et al. Applications of ultrafast nano-spectroscopy and nano-imaging with tip-based microscopy. eLight. 2025;5(1). doi:10.1186/s43593-024-00079-1
  34. Dincer I, Ishaq H. Solar Energy-Based Hydrogen Production. Renewable Hydrogen Production. 2022:91-122. doi:10.1016/b978-0-323-85176-3.00009-3