Nav: Home

Syracuse University chemists add color to chemical reactions

May 18, 2016

Chemists at Syracuse University have come up with an innovative new way to visualize and monitor chemical reactions in real time.

Members of the Maye Research Group in the Department of Chemistry have designed a nanomaterial that changes color when it interacts with ions and other small molecules during a chemical reaction.

The subject of an article in ACS Nano (American Chemical Society, 2016), their discovery enables researchers to monitor reactions qualitatively with the naked eye and quantitatively with simple instrumentation.

"In many cases, a chemical reaction between molecules occurs in a solution that is colorless and transparent or looks like a milky suspension," says Mathew Maye, associate professor of chemistry and the experiment's team leader. "The only way to know if a reaction has occurred or not is to perform extensive analysis after a multi-step purification."

In an attempt to figure out why and how fast a reaction occurs (if at all), the group has designed a nanoparticle that reacts with byproducts of the reaction. "When the reactions occurs, the nanoparticle fluoresces at a different color, allowing us to gauge kinetics by eye, instead of with a million-dollar spectrometer," Maye says.

Central to the group's work is an emerging class of nanomaterials called perovskites. A perovskite is a special class of crystal, typically made up of metal ions and oxygen. The group's perovskites are composed of metal ions and a halide.

At the nanoscale, perovskites are photo-luminescent, meaning that they emit light when "excited" by a laser or lamp. That the colors they emit are determined, in part, by their ion concentrations makes perovskites unique among nanomaterials.

It also makes them ripe for application. Research groups in industry and academia see potential for perovskites in solar cells, light-emitting diodes, lasers and photo detectors.

Tennyson Doane, a post-doctoral researcher in the group, is the article's co-corresponding author with Maye. "We knew about the potential of these materials in energy research," Doane says. "We are interested in energy as well, and had this crazy idea of trying to use the ion concentration ratios of perovskites to detect ions in solution, and then perhaps monitor the chemical reaction, which is very difficult to do. We had no idea if it would work or not, so we just decided to go for it."

The group started by working with a very simple system that involved organic reactions of molecules called organohalides. When these molecules react, often forming carbon-carbon double bonds in what is known as an elimination reaction, the halide is released. (The halide is a bromine, chlorine or iodine ion.) Typically, the halide is an unimportant side-product of the reaction, until now.

"Our technology allows us to accurately detect the halide release," says Kevin Cruz '18, a chemistry major and co-author of the article. "When the reaction starts, the perovskite fluoresces bright red. As the halide is released, or exchanged in the chemical reaction, our particle absorbs it, and the fluorescence color changes proportionally to the halide concentration--from red to orange to yellow to green. When the color is green, the reaction is over."

Explains Doane: "Added to that is the fact that the perovskite concentration is very low, you just have to add a small amount to the reaction for observation. We have been able to calibrate the system very accurately, and from that can measure chemical kinetics in a new 'colorimetric' way."

Maye offers nothing but praise for Doane and Cruz, stating that what they have accomplished in a short amount of time and on a small budget is "amazing."

"No one, right now, is thinking about monitoring a chemical reaction this way," Maye adds. "Our team is able to measure very precise chemical kinetics by monitoring the color change with nothing more than an ultraviolet lightbulb or a cheap fluorescence spectrometer."

In addition to Doane, Cruz and Maye, the article was co-written by Kayla Ryan G'15, Ph.D. student Laxmikant Pathade and Huidong Zang and Mircea Cotlet at the Center for Functional Nanomaterials at Brookhaven National Laboratory, each of whom made important measurements in the study.

The group's technology is patent-pending at the University. Maye says they are testing the approach's applicability to a wide library of chemical reactions and its effectiveness at measuring low concentrations of ions and reactive molecules.

"Who knows, maybe in the future, every chemist will use a Syracuse-based perovskite for monitoring their reactions," he adds.

Syracuse University

Related Chemical Reactions Articles:

Caught on camera -- chemical reactions 'filmed' at the single-molecule level
Scientists have succeeded in 'filming' inter-molecular chemical reactions -- using the electron beam of a transmission electron microscope as a stop-frame imaging tool.
Study: Some catalysts contribute their own oxygen for reactions
New MIT research shows that metal-oxide catalysts can sometimes release oxygen from within their structure, enhancing chemical activity.
Chemists uncover a means to control catalytic reactions
Scientists at the University of Toronto have found a way to make catalysis more selective, breaking one chemical bond 100 times faster than another.
Deep insights from surface reactions
Using the Stampede supercomputer at the Texas Advanced Computing Center, researchers have developed biosensors that can speed up drug development, designed improved materials for desalinization, and explored new ways of generating energy from bacteria.
Scientists trace 'poisoning' in chemical reactions to the atomic scale
A combination of experiments, including X-ray studies at Berkeley Lab, revealed new details about pesky deposits that can stop chemical reactions vital to fuel production and other processes.
How solvent molecules cooperate in reactions
Molecules from the solvent environment that at first glance seem to be uninvolved can be essential for chemical reactions.
Scientists rev up speed of bionic enzyme reactions
Bionic enzymes got a needed boost in speed thanks to new research at the Berkeley Lab.
Adverse drug reactions may be under-reported in young children
A new study reveals that adverse drug reactions in newborns and infants may be under-reported.
New model predicts once-mysterious chemical reactions
A team of researchers from Los Alamos National Laboratory and Curtin University in Australia developed a theoretical model to forecast the fundamental chemical reactions involving molecular hydrogen.
Syracuse University chemists add color to chemical reactions
Members of the Maye Research Group at Syracuse University have designed a nanomaterial that changes color when it interacts with ions and other small molecules during a chemical reaction.

Related Chemical Reactions Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Don't Fear Math
Why do many of us hate, even fear math? Why are we convinced we're bad at it? This hour, TED speakers explore the myths we tell ourselves and how changing our approach can unlock the beauty of math. Guests include budgeting specialist Phylecia Jones, mathematician and educator Dan Finkel, math teacher Eddie Woo, educator Masha Gershman, and radio personality and eternal math nerd Adam Spencer.
Now Playing: Science for the People

#518 With Genetic Knowledge Comes the Need for Counselling
This week we delve into genetic testing - for yourself and your future children. We speak with Jane Tiller, lawyer and genetic counsellor, about genetic tests that are available to the public, and what to do with the results of these tests. And we talk with Noam Shomron, associate professor at the Sackler School of Medicine at Tel Aviv University, about technological advancements his lab has made in the genetic testing of fetuses.