Light-Matter Interactions in Molecular Photochemistry

Year : 2025 | Volume : 03 | Issue : 02 | Page : 33 42
    By

    Sandeep Rai,

  1. Doctoral Progress Committee [DPC], Department of Chemistry, UPL University of Sustainable Technology, Vataria, Ankleshwar, Bharuch, Gujarat, India

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: Photochemistry, photo-catalysis, solar energy conversion, molecular optoelectronics, molecular switches / photo-isomerization devices

[This article belongs to International Journal of Photochemistry and Photochemical Research ]

How to cite this article:
Sandeep Rai. Light-Matter Interactions in Molecular Photochemistry. International Journal of Photochemistry and Photochemical Research. 2025; 03(02):33-42.
How to cite this URL:
Sandeep Rai. Light-Matter Interactions in Molecular Photochemistry. International Journal of Photochemistry and Photochemical Research. 2025; 03(02):33-42. Available from: https://journals.stmjournals.com/ijppr/article=2025/view=234477


References

  1. Christian George, Martin Brüggemann, Nathalie Hayeck, Liselotte Tinel, James Donaldson, Chapter 14 – Interfacial Photochemistry, Editor[s]: Jennifer A. Faust, James E. House, In Developments in Physical & Theoretical Chemistry, Physical Chemistry of Gas-Liquid Interfaces, Elsevier, 2018, Pages 435-457, ISBN 9780128136416, https://doi.org/10.1016/B978-0-12-813641-6.00014-5. [https://www.sciencedirect.com/science/article/pii/B9780128136416000145]
  2. https://microbiozindia.com/the-fundamentals-of-photochemistry-understanding-the-basics/
  3. McLaughlin, J.D. Glennon, Analytical Methods | Spectroscopy, Overview, Editor[s]: John W. Fuquay, Encyclopedia of Dairy Sciences [Second Edition], Academic Press, 2011, Pages 109-114, ISBN 9780123744074, https://doi.org/10.1016/B978-0-12-374407-4.00010-8. [https://www.sciencedirect.com/science/article/pii/B9780123744074000108]
  4. https://journals.aps.org/prb/abstract/10.1103/PhysRevB.73.241406
  5. Yehuda B. Band, Yshai Avishai, 3 – Angular Momentum and Spherical Symmetry, Editor[s]: Yehuda B. Band, Yshai Avishai, Quantum Mechanics with Applications to Nanotechnology and Information Science, Academic Press, 2013, Pages 105-157, ISBN 9780444537867, https://doi.org/10.1016/B978-0-444-53786-7.00003-4. [https://www.sciencedirect.com/science/article/pii/B9780444537867000034]
  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. John C. Traeger, Photoionization and Photodissociation Methods in Mass Spectrometry, Editor[s]: John C. Lindon, Encyclopedia of Spectroscopy and Spectrometry, Elsevier, 1999, Pages 1840-1847, ISBN 9780122266805, https://doi.org/10.1006/rwsp.2000.0239. [https://www.sciencedirect.com/science/article/pii/B0122266803002398]
  11. Siva Subramaniam Iyer, Chapter 15 – The role of excited states in deciphering molecules and materials: time-resolved electronic spectroscopic studies, Editor[s]: V.P. Gupta, Yukihiro Ozaki, Molecular and Laser Spectroscopy, Elsevier, 2020, Pages 521-562, ISBN 9780128188705, https://doi.org/10.1016/B978-0-12-818870-5.00015-0. [https://www.sciencedirect.com/science/article/pii/B9780128188705000150]
  12. Karel Klepárník, František Foret, Recent advances in the development of single cell analysis—A review, Analytica Chimica Acta, Volume 800, 2013, Pages 12-21, ISSN 0003-2670, https://doi.org/10.1016/j.aca.2013.09.004. [https://www.sciencedirect.com/science/article/pii/S0003267013011756]
  13. Skourtis SS, Liu C, Antoniou P, Virshup AM, Beratan DN. Dexter energy transfer pathways. Proc Natl Acad Sci U S A. 2016 Jul 19;113[29]:8115-20. doi: 10.1073/pnas.1517189113. Epub 2016 Jul 5. PMID: 27382185; PMCID: PMC4961191.
  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? Proc Natl Acad Sci U S A. 1970 Jun;66[2]:257-64. doi: 10.1073/pnas.66.2.257. PMID: 16591837; PMCID: PMC283037.
  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. 3 – The coupling methods, Editor[s]: Qun Zhang, Song Cen, In Elsevier and Tsinghua University Press Computational Mechanics Series, Multiphysics Modeling, Academic Press, 2016, Pages 125-156, ISBN 9780124077096, https://doi.org/10.1016/B978-0-12-407709-6.00003-1. [https://www.sciencedirect.com/science/article/pii/B9780124077096000031]
  20. https://www.mdpi.com/20763417/12/18/9238#:~:text=In%20practice%2C%20perfectly%20lossless%20cavities,high%2Dfinesse%20cavities%20are%20required.
  21. Litinskaya, Polaritons, Editor[s]: Franco Bassani, Gerald L. Liedl, Peter Wyder, Encyclopedia of Condensed Matter Physics, Elsevier, 2005, Pages 334-341, ISBN 9780123694010, https://doi.org/10.1016/B0-12-369401-9/00663-X. [https://www.sciencedirect.com/science/article/pii/B012369401900663X]
  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, Z.T., Pannir-Sivajothi, S., Yim, J.E. et al. Vibrational weak and strong coupling modify a chemical reaction via cavity-mediated radiative energy transfer. Chem. 17, 439–447 [2025]. https://doi.org/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. Roya Darabi, Erfan Azinpour, Ana Reis, Jose Cesar de Sa, Multi-scale Multi-physics Phase-field coupled Thermo-mechanical approach for modeling of powder bed fusion process, Applied Mathematical Modelling, Volume 122, 2023, Pages 572-597, ISSN 0307-904X, https://doi.org/10.1016/j.apm.2023.06.021. [https://www.sciencedirect.com/science/article/pii/S0307904X23002767]
  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. et al. Applications of ultrafast nano-spectroscopy and nano-imaging with tip-based microscopy. eLight 5, 1 [2025]. https://doi.org/10.1186/s43593-024-00079-1
  34. Ibrahim Dincer, Haris Ishaq, Chapter 3 – Solar Energy-Based Hydrogen Production, Editor[s]: Ibrahim Dincer, Haris Ishaq, Renewable Hydrogen Production, Elsevier, 2022, Pages 91-122, ISBN 9780323851763, https://doi.org/10.1016/B978-0-323-85176-3.00009-3. [https://www.sciencedirect.com/science/article/pii/B9780323851763000093

https://www.allaboutcircuits.com/technical-articles/an-introduction-to-optoelectronics/#:~:text=Summary,light%20[optoisolators%20and%20phototransistors]

Regular Issue Subscription Review Article
Volume 03
Issue 02
Received 15/10/2025
Accepted 20/10/2025
Published 17/12/2025
Publication Time 63 Days
154

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