Damrauer

Light-powered reactions could make the chemical manufacturing industry more energy-efficient

Daniel Morton — Thu, 26 Jun 2025 22:25:34 +0000

Light-powered reactions could make the chemical manufacturing industry more energy-efficient Daniel Morton Thu, 06/26/2025 - 16:25

Daniel Morton

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A recent collaborative report, published in Science, including RASEI Fellow Niels Damrauer, addresses a key issue for light-driven chemistry, potentially opening up possibilities for future energy-efficient chemical manufacturing.

Chemical reactions typically require an input of energy to proceed, this can be through heating, or introduction of chemical energy in the form of reactive chemicals. Recently, light-driven chemistry has emerged as a more energy efficient alternative. The principle is to use energy from light, which is absorbed by a catalyst. Excited by the light energy the catalyst can then donate an electron to the chemicals undergoing the desired chemical transformation.

This sounds great – light-driven reactions? One of the key issues in this class of chemistry is back transfer of the electron. This means that after the catalyst donates the electron to the reagents, instead of doing the desired reaction, the reagent gives the electron back to the catalyst. This can significantly slow down the desired reaction, even sometimes shutting it down.

This report details a new type of catalyst that can overcome this back transfer of electrons. Through rationale design of the catalyst the new system uses a chemical reaction as a catch, preventing the back transfer from the reagent and strongly favoring the desired reaction.

To highlight the impact of this work, which was completed as part of the NSF Center for Chemical Innovation Center for Sustainable Photoredox Catalysis (SuPRCat), CU Boulder student Arindam Sau, a member of the Damrauer group, teamed up with a graduate student and postdoc from Colorado State University to put together a review and summary of this work that was recently published in The Conversation. Check out the highlight to get a full picture of the impact of this work.

June 2025

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Efficient super-reducing organic photoredox catalysis with proton-coupled electron transfer mitigated back electron transfer

Daniel Morton — Thu, 19 Jun 2025 17:38:42 +0000

Efficient super-reducing organic photoredox catalysis with proton-coupled electron transfer mitigated back electron transfer Daniel Morton Thu, 06/19/2025 - 11:38

SCIENCE, 2025, 388, 6753, 1294-1300

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Supercharging Chemistry: A jump forward in light-driven chemistry

Daniel Morton — Sat, 07 Jun 2025 16:28:32 +0000

Supercharging Chemistry: A jump forward in light-driven chemistry Daniel Morton Sat, 06/07/2025 - 10:28

Daniel Morton

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New collaborative research involving RASEI Fellow Niels Damrauer, addresses one of the ‘house of cards’ problems sometimes critical in photoredox catalysis.

Think about how you build a house of cards, every time you add a new card, there is a chance the whole thing will fall apart. This is a challenge often faced by chemists when they are trying to put together the components needed for a light-driven reaction. While this type of chemistry has huge potential in making the chemistry cleaner and more efficient, one of the features that can cause the whole thing to fall apart is a phenomenon called back electron transfer, where the desired chemical reaction is reversed, wasting energy and limiting the kinds of reaction that can be performed.

This collaborative team that includes RASEI Fellow Niels Damrauer from CU Boulder and the groups of Garret Miyake and Robert Paton from Colorado State University in Fort Collins, has developed a new catalyst system that overcomes this fundamental obstacle. Published in a recent issue of Science, this work introduces a ‘super-reducing’ organic photoredox catalyst that, through preventing this backward reaction, opens the door to powerful new redox chemistries.

To better understand this discovery it is useful to think of the process like filling a bucket with water. In typical photoredox reactions, the bucket has a leak. As water is poured into the bucket (adding energy from light), some of it immediately drains out. This ‘leak’ is back electron transfer (BET), and it is especially problematic for complex and difficult reactions that require a lot of energy – it is like trying to fill a very leaky bucket with a very slow faucet.

The research collaboration, part of the National Science Foundation (NSF) funded Center for Chemical Innovation (CCI) Center for Sustainable Photoredox Catalysis (SuPRCat) took inspiration from nature to develop a solution for this problem. In photosynthesis plants use a process called proton-coupled electron transfer (PCET) to efficiently capture and store energy from sunlight, preventing energy loss. The team used a combination of sophisticated computational modeling and experimental investigation to design a catalyst that incorporates a similar mechanism. When the catalyst is energized by light it simultaneously transfers an electron to the target molecule and releases a proton (a hydrogen atom without its electron). This prevents the reaction from going backwards. This small change has a huge impact on how the reaction proceeds, it is essentially like patching the leak in the bucket as you pour the water in, ensuring that all the energy is used for the desired reaction.

As is often the case with research, the path to this discovery was not a straight line. The investigations initially focused on changing an existing catalyst framework. During these experiments they noticed that one of the new catalysts (PC40Me) was unexpectedly effective. The reduction of benzene is known to be a difficult transformation, but reactions catalyzed with PC40Me were possible. They found that under the reaction conditions PC40Me was transforming into a new chemical structure, and it was this new system that was efficient for the historically difficult reduction of benzene. Armed with this knowledge the team built new catalyst designs around the new structure, creating a more efficient catalyst (named PC8). PC8 is not only a ‘super reducer’ capable of reducing a broad range of aromatic compounds under mild conditions, it also proved to be extremely robust.

The key features of this work lies in its potential to be a new tool in how we design and build everything from pharmaceuticals to plastics. By providing a way to perform these difficult reduction reactions more efficiently and sustainably, this catalyst system has the potential to reduce waste and energy consumption. By opening the door to a transformation that has typically been thought of as difficult and un-efficient, it could act as an enabling technology in the synthesis of new classes of molecules that were previously out of reach.

This work highlights the power of collaboration. The combination of different tools and approaches that were required to complete this work would have been prohibitive for a single research group. By combining expertise the team were able to unravel this complex chemical puzzle, not only demonstrating a new transformation, but providing some design rules that can be used by future photocatalysis practitioners in reducing BET.

JUNE 2025

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Unfiltered Broadband Probes Can Obscure Long Time Dynamics in Populations Engaged in Second-Order Processes Including Annihilation

Daniel Morton — Mon, 03 Mar 2025 22:52:55 +0000

Unfiltered Broadband Probes Can Obscure Long Time Dynamics in Populations Engaged in Second-Order Processes Including Annihilation Daniel Morton Mon, 03/03/2025 - 15:52

THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 2025, 16, 2522-2528

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Shining new light on an old problem: Breaking down ‘Forever Chemicals’ and building the next generation of materials

Daniel Morton — Wed, 15 Jan 2025 17:04:08 +0000

Shining new light on an old problem: Breaking down ‘Forever Chemicals’ and building the next generation of materials Daniel Morton Wed, 01/15/2025 - 10:04

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Using a new catalyst and visible light, researchers have developed a chemical “scalpel” to degrade persistent pollutants and enable new, more precise chemical reactions.

The global challenge of “forever chemicals” has made the headlines for years. The carbon-fluorine (C–F) bond is one of the strongest in all of chemistry. For decades the sheer strength of the C–F bond has been a blessing and a curse. This incredible strength is what makes “forever chemicals”, like PFAS, so stable and useful in everything from non-stick pans to waterproof clothing but is also the reason that they are nearly impossible to break down. This has been a major contributor to the growing plastic waste crisis, and a key reasons for these compounds to be now known as one of the hardest pollutants to remove from the environment. A recent collaborative study, including RASEI Fellow Niels Damrauer, has a new solution for this problem. Development of a new catalyst that acts like a chemical scalpel, using blue light to precisely sever this famously inert bond. This approach not only offers a new way to degrade these persistent pollutants but also opens the door to using what were previously considered unreactive fluorinated molecules as building blocks for new chemical transformations and products.

This study is an illustrative example of a modern, collaborative approach to chemical innovation, as part of the NSF funded Center for Sustainable Photoredox Catalysis (SuPRCat). The research team came at the problem from two different angles: computational modeling and hands-on experimentation. The computational chemists first used powerful simulations to design and predict the behavior of a new organic catalyst. This helped them understand exactly how the catalyst could use low-energy, visible blue light to act as our "chemical scalpel," targeting and breaking the C–F bonds without the need for intense heat.

With this knowledge, the experimental chemists then created the catalyst in the lab. They showed that it could precisely snip the C-F bonds in a variety of molecules, demonstrating it was capable of both degrading persistent pollutants like PFAS and building new chemical structures that were previously difficult to construct.

The success of this research with a simple, abundant energy source like visible light shows that chemical reactions don’t have to be energy intensive. This research describes the power of precise, light-driven chemistry. By designing a catalyst that can target and activate some of the toughest bonds in chemistry, this team has not only revealed a potential path forward for degrading PFAS, but also demonstrated a new tool for chemists to build molecules in a cleaner and more energy efficient way.

JANUARY 2025

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Catalyzing the Sustainable Decomposition of PFAS Forever Chemicals

Daniel Morton — Sat, 21 Dec 2024 00:30:44 +0000

Catalyzing the Sustainable Decomposition of PFAS Forever Chemicals Daniel Morton Fri, 12/20/2024 - 17:30

Daniel Morton

RASEI Fellow Niels Damrauer is part of a collaborative team that have developed a new light-driven C-F activation reaction, one that has the potential to help dismantle PFAS ‘forever chemicals’

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Perfluoroalkyl and polyfluoroalkyl substances, or PFAS, are synthetic compounds that have found widespread use in consumer products and industrial applications. Their water and grease resistant properties have been part of their attraction in their applications, but these are also the reason that they are now found practically everywhere in the environment, they are very difficult to decompose.

While many chemicals will decompose relatively quickly, studies have shown that PFAS are expected to stick around for up to 1000 years. While this durability is great in something like firefighting foams or non-stick cookware, it is not great when these compounds get into the environment.

This new article, published in Nature in November of 2024, describes the work of a collaborative team of theoretical and experimental chemists, who have developed a new photochemical reaction that could hold promise of speeding up the decomposition of PFAS. A recent highlight of this work, written by the graduate student and postdoctoral fellows who did the research, appeared in The Conversation.

Using a photocatalyst, that absorbs light to speed up a reaction, the researchers were able to ‘activate’ one of the carbon-fluorine bonds, one of the strongest bonds in organic chemistry. The photocatalyst absorbs light, transfers electrons to the fluorine containing molecules, which then breaks down the sturdy carbon-fluorine bond.

While this doesn’t decompose the whole molecule, it is essentially like finding a chink in the armor, it opens the door to degradation of the PFAS to harmless smaller molecules.