Enhanced Photodimerization of Organic Molecules in Water Demonstrated

Strategic Insights -

Researchers from the Department of Chemistry, KREA University, have conducted a study on the photodimerization of organic molecules such as indene and coumarin in water. The study found that this process is dramatically enhanced in water compared to an organic solvent. The researchers used NMR spectroscopy, dynamic light scattering experiments, quantum chemical calculations, and molecular dynamic simulations to investigate the origin of this phenomenon. They found that indene molecules exist as an equilibrium mixture of monomers, noncovalent dimers, and small aggregates in water, which is different from their behavior in an organic solvent.

Key Takeaways:

  • The photodimerization of organic molecules such as indene and coumarin is enhanced in water compared to an organic solvent.
  • Indene molecules exist as an equilibrium mixture of monomers, noncovalent dimers, and small aggregates in water.
  • This behavior is distinctly different from that observed in an organic solvent, where indene molecules remain homogeneously distributed as monomers.
  • The enhancement of thermal bimolecular reactions such as the Diels-Alder reaction can be analyzed in terms of "in-water", "on-water", and "on the surface of microdroplets".
  • The presence of small aggregates, detectable by their unusually sharp H NMR signals, rules out the need for diffusion, which is often slower than the decay rates of excited molecules.
  • This research has implications for understanding reactions in water and may lead to new insights into the behavior of small organic molecules in aqueous environments.
  • Vaidhyanathan Ramamurthy and Narayanasami Sathyamurthy are among the researchers involved in this study.
  • Brijesh Kumar Mishra is the contact person for further information.

Statistics:

  • The research was conducted in the Department of Chemistry at KREA University, Scri City, Andhra Pradesh, India.
  • 5 researchers were involved in this study: Brijesh Kumar Mishra, Vaitheesh Jeyapalan, Sreerag N. Moorkkannur, Rajeev Prabhakar, and Vaidhyanathan Ramamurthy.
  • The study used NMR spectroscopy, dynamic light scattering experiments, quantum chemical calculations, and molecular dynamic simulations.
  • The enhancement of thermal bimolecular reactions such as the Diels-Alder reaction was analyzed in terms of "in-water", "on-water", and "on the surface of microdroplets".

Sources:

  • Consequences of Heterogeneity of Organic Molecules in Water: Enhanced Photodimerization of Olefins. Langmuir, 2025.
  • NewsRx. Reports Summarize Technology Findings from Department of Chemistry (Consequences of Heterogeneity of Organic Molecules in Water: Enhanced Photodimerization of Olefins). Journal of Engineering. October 20, 2025; p 2759.