Research Highlights

Biophysics | Nanoscience
How to Bind with Metals and Water: A New Study on EDTA
The near-universal ability of EDTA to accommodate metal cations comes from its molecular flexibility, which allows it to respond to the chemical nature of the metal ion it binds.
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Metal ions can be found in almost every environment, including wastewater, chemical waste and electronic recycling waste. Properly recovering and recycling valuable metals from various sources is crucial for sustainable resource management and contributes to environmental cleanup. Because of the scarcity of some of these metals, such as rare earth elements or nickel, scientists are working to find ways to remove these ions from the waste and recycle the metals. One method used to remove these metals is to bind them to other molecules known as chelators or chelating agents. Chelators have multiple molecular groups that combine to form binding sites with a natural affinity for binding metal ions, making them a natural choice to extract metals from toxic waste. Ethylenediaminetetraacetic acid, or EDTA, is a chelator commonly used in metal removal and many other applications, including medicine. “EDTA is used to treat heavy-metal poisoning,” JILA graduate student Lane Terry explained. “So, if you have lead poisoning, you can take EDTA, which binds to the lead and then safely passes through your system. It's also used as a food preservative. So EDTA is everywhere. It's in one of my topical creams, etc.” EDTA is also commonly used in various laboratories, including many within JILA. 

To understand how EDTA binds to these metal ions and water molecules, Madison Foreman, a former JILA graduate student in the Weber group, now a postdoctoral researcher at the University of California, Berkeley, Terry, and their supervisor, JILA Fellow J. Mathias Weber, studied the geometry of the EDTA binding site using a unique method that helped to isolate the molecules and their bound ions, allowing for more in-depth analyses of the binding interactions. They published a series of three papers on this topic. In their first paper, published in the Journal of Physical Chemistry A, they found that the size of the metal ion changes where it sits in the EDTA binding site, which affects other binding interactions, especially with water. 

PI: J. Mathias Weber
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Chemical Physics
The Rules of Photon Thunderdome
two triplet-state ions eliminate each other to create an excited singlet which fluoresces
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During upconversion photoluminescence in rubrene, four triplet state ions fight it out to release a single high-energy photon. 

PI: J. Mathias Weber
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Chemical Physics
Recreating Fuels from Waste Gas
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Graduate student Mike Thompson of the Weber group wants to understand the basic science of taking carbon dioxide (CO2) produced by burning fossil fuels and converting it back into useful fuels. People could then use these fuels to generate electricity, heat homes and office buildings, power automobiles and trains, fly airplanes, and drive the industrial processes of modern life.

PI: J. Mathias Weber
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Chemical Physics
Refueling the Future - with Carbon Dioxide
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Graduate student Ben Knurr and Fellow Mathias Weber have added new insight into a catalytic reaction based on a single gold atom with an extra electron that transfers this electron into carbon dioxide molecules (CO2). This reaction could be an important first step future industrial processes converting waste CO2 back into chemical fuels. As such, it could play a key role in a future carbon-neutral fuel cycle.

PI: J. Mathias Weber
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Chemical Physics
Good Vibrations
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Mathias Weber and his team recently did the following experiment: They excited the methyl group (CH3) on one end of nitromethane anion (CH3NO2-) with an infrared (IR) laser. The laser got the methyl group vibrating with enough energy to get the nitro group (NO2) at the other end of the molecule wagging hard enough to spit out its extra electron.

PI: J. Mathias Weber
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Chemical Physics
A Light Changing Experience
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The Weber group wants to understand how the individual building blocks of DNA interact with ultraviolet (UV) light. Such knowledge would be an important step toward gaining a detailed understanding of the molecular processes responsible for the UV-induced DNA damage that results in mutations and can lead to cancer or cell death.

PI: J. Mathias Weber
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Chemical Physics
One Ring to Rule Them All
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Benzene has a special ring structure that allows some of its electrons to be shared among all six carbon atoms in the ring. It turns out that chemists like Fellow J. Mathias Weber can adjust the charge density in the ring by exchanging hydrogen (H) atoms in the ring with other atoms or groups of atoms. Such exchanges can change the charge pattern in the ring "seen" by neighboring molecules.

PI: J. Mathias Weber
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