New Method Replaces Toxic Solvents with Water for Chemical Synthesis

Rice University rresearchers have developed a method for conducting chemical reactions using water instead of hazardous solvents. By designing metal complex surfactants (MeCSs) that self-assemble into nanoscale micelles, the researchers created microscopic reactors capable of supporting light-driven chemical reactions. The study was published in Chemical Science.

This approach aims to reduce pollution in industries such as materials science and pharmaceuticals, where organic solvents are commonly used. The micellar system facilitates reactions in aqueous environments, even with substances that are typically insoluble in water. The research team, led by Rice Professor and Chair of Chemistry Angel Martí, demonstrated that this system can effectively perform photocatalytic reactions without relying on hazardous materials.

Our findings show how powerful molecular design can be in tackling chemical sustainability challenges while maintaining high chemical performance. We’ve created a tool that could transform how chemical reactions are performed, reducing environmental harm while increasing efficiency.

Angel Martí, Professor and Chair, Chemistry, Rice University

How the Discovery Works

Surfactants are molecules with both hydrophilic and hydrophobic regions. In water, they spontaneously form micelles, with the hydrophobic regions clustering at the core to create a confined reaction environment. Researchers modified these surfactants by incorporating a light-sensitive metal complex, resulting in MeCSs.

To evaluate different configurations, the team varied the length of the MeCS hydrophobic tails. They found that these molecules could form micelles as small as 5–6 nm. Using these micelles in a photocatalytic reaction, the system achieved high yields without requiring organic solvents.

These micelles act like tiny reaction vessels. They enable chemical transformations that wouldn’t normally work in water while being more sustainable than traditional methods.

Ying Chen, Study First Author and Doctoral Student, Department of Chemistry, Rice University

Why This Matters

Many chemical processes in research and manufacturing rely on organic solvents, which pose environmental and safety concerns. The development of photoactive, water-based micelles offers a safer and more sustainable alternative. Additionally, the system’s reusability enhances both its environmental and economic viability.

The study was co-authored by Shih-Chieh Kao and Julian West from Rice’s Department of Chemistry, Asia Matatyaho Ya’akobi and Yeshayahu Talmon from the Technion-Israel Institute of Technology, and Thao Vy Nguyen and Sibani Lisa Biswal from Rice’s Department of Chemical and Biomolecular Engineering. The research was supported by the Welch Foundation and Rice’s Interdisciplinary Excellence Awards.

Journal Reference:

Chen, Y., et al. (2025) Supramolecular self-assembly of metal complex surfactants (MeCS) into micellar nanoscale reactors in aqueous solution. Chemical Science. doi.org/10.1039/D4SC07623K