light-driven chemistry, once reliant on rare and toxic metals like ruthenium or iridium, has taken a sustainable leap forward. Researchers have created a new manganese-based complex that’s easy to synthesize, absorbs light exceptionally well, and maintains a record-breaking excited-state lifetime. Credit: Shutterstock
A new manganese(I) complex sets a record for the longest excited-state lifetime, opening the door to future large-scale applications in photochemistry.
Chemical reactions are often powered by heat, but scientists have increasingly turned to light as an energy source because it allows reactions to be guided with remarkable precision. This light-based process is called photochemistry.
Until recently, photochemical reactions depended on rare and costly metals such as ruthenium, osmium, or iridium, which also pose environmental challenges during extraction. Now, researchers at Johannes Gutenberg University Mainz (JGU) have created a groundbreaking metal complex that uses manganese-an element that is both abundant and inexpensive.
“This metal complex sets a new standard in photochemistry: it combines a record-breaking excited-state lifetime with simple synthesis,” stated Professor Katja Heinze from the JGU Department of Chemistry. “It thus offers a powerful and sustainable alternative to the noble metal complexes that have long dominated light-driven chemistry.”
Their findings were recently published in Nature Communications.
Single-step synthesis and strong absorption
Although manganese is more than 100,000 times more common on earth than ruthenium, its use in photochemistry has long been limited. This was largely due to the complex, multi-step synthesis process, often requiring nine or ten stages, and the very short lifetime of its excited state.
“The newly developed manganese complex overcomes both challenges,” explained Dr. Nathan East,a former doctoral student in the Heinze group who carried out the original synthesis. The new material is synthesized directly from commercially available starting materials – in just a single synthesis step.
In addition to manganese, the researchers use a ligand, which allows the properties of the complex to be tuned.
