Blog – Page 3

Carbon’s unique chemical properties allow it to be an essential building block for life on Earth and many other molecules we rely on for day-to-day life—but what about carbon’s neighbor? Silicon is located one row below carbon in the periodic table of elements, and similarly has many possible uses, and is a key component of semiconductors, silicon carbide fibers, and silicones. However, silicon has some key weaknesses compared to carbon.

For example, carbon forms very stable π-electron compounds (compounds linked by pi bonds, or π-bonds, which affect a molecule’s reactivity) called benzene and fullerene. In comparison, silicon cannot readily form these compounds, as the π-bonds forming π-electron compounds are not strong in this element. Synthesizing such silicon-based π-electron compounds consequently becomes increasingly difficult as the number of silicon atoms increases. However, researchers at Tohoku University found a way to overcome these limitations.

A research group led by Professor Takeaki Iwamoto, Graduate Student Tomoki Ishikawa, and Associate Professor Shintaro Ishida at the Graduate School of Science, Tohoku University, has successfully synthesized π-electron compounds with a pentagonal silicon framework, “pentasilacyclopentadienide,” and elucidated their molecular structures. The study is published in the journal Science.

Iridium oxide is one of the most important—and most problematic—materials in the global push toward clean energy. It is currently the most reliable catalyst used in the conversion of energy to chemicals by electrolysis, a process that uses electricity to split water molecules into oxygen and hydrogen.

But iridium is among the rarest non-radioactive elements in Earth’s crust, and not unlike metal rusting over time, iridium oxide catalysts slowly degrade under the harsh acidic and high-voltage conditions required for electrolyzers (the devices used for electrolysis) to operate.

A new study by researchers at Duke University and the University of Pennsylvania offers an unprecedented view of that degradation process, capturing how iridium oxide nanocrystals restructure and dissolve—atom by atom—during electrolysis. The findings provide critical insight into why today’s best catalysts still fail and how future materials might last longer. The study is published in the Journal of the American Chemical Society.

UCLA chemists proved that some of chemistry’s oldest rules can be broken—and new molecules emerge when they are.

Organic chemistry is built on well-known principles that describe how atoms connect, how chemical bonds form, and how molecules take shape. These rules are often treated as firm boundaries that define what structures are possible. Researchers at UCLA, however, are showing that some of these limits are more flexible than long assumed.

Challenging a Century Old Rule.