image: A figure shows a molecule containing gold bonded to ethylene stabilized by a supporting ligand. view more
Credit: Dr. Rasika Dias/UT Arlington
A UT Arlington professor will use a new $450,000 National Science Foundation grant to develop new chemical processes and technologies based on a better understanding of the way that metals such as gold, silver, mercury and zinc bind with organic compounds for chemical reactions.
The three-year project involves reactions used widely in industry and research laboratories. The principal investigator is Rasika Dias, distinguished professor and chairman of The University of Texas at Arlington Department of Chemistry and Biochemistry.
Dias' work will explore the interaction between six metals found in the right section of the Periodic Table of Elements' d-block and what are called pi-acid ligands, which include familiar organic compounds like carbon monoxide, ethylene, acetylene and the related olefins and alkynes. These carbon based molecules bind to metal through interaction of their electrons, becoming what is known scientifically as ligands.
In many cases, the combination of a specific d-block element and pi-acid ligands creates a situation favorable for chemical reactions with molecules like oxygen, hydrogen chloride, and even water. The metals essentially act as a catalyst in the creation of new products.
These reactions can create valuable industrial chemicals such as ethylene oxide, chloroethene and alcohols. Ethylene oxide is used in producing solvents, textiles, detergents, adhesives and pharmaceuticals. Chlorethene is used to make polyvinyl chloride or PVC, a widely used plastic. In other instances, metals like gold provide a way to remove harmful chemicals like carbon monoxide by converting it to carbon dioxide through an oxidation process.
"What we are trying to do is to understand how these metals act as catalysts and create a lower energy pathway for these reactions to occur. If we can understand that, we can control the reaction to obtain better product yields under milder conditions or to eliminate the formation of unnecessary by-products," Dias said. "We may even find a way to direct reactions to a completely new pathway leading to even more useful products and molecules. Overall, through this work, we hope to create more energy efficient, sustainable and selective processes and develop new technology."
Dias will study the bonding and chemistry of zinc, copper, cadmium, silver, mercury and gold with alkene and alkyne compounds and carbon monoxide. The first phase of the lab's work will involve getting a better understanding of the electronic structure - how electrons are exchanged, distributed and shared between the metal and the ligand. They will also observe the structural effects of the interactions.
Some of the metals Dias is working with also facilitate the reaction of pi-acid molecules with each other, such as alkenes reacting with alkynes, leading to very useful and yet more complicated compounds used in pharmaceutical industry.
Dias' lab specializes in stabilizing usually reactive or unstable molecules so that they are stable enough to examine using a method called X-ray crystallography.
"Our dream is to find efficient ways of breaking and making bonds in and between molecules selectively to get what we want," he said.
Dias' team has already experienced noted success, publishing x-ray crystal structures that revealed new information about compounds featuring gold-ethylene and gold-carbon monoxide bonds in journals such as Angewandte Chemie-International Edition, Organometallics, and Inorganic Chemistry, which is based upon work supported by the prior National Science Foundation Grant CHE-0845321.
"Dr. Dias is focused on fueling advances in basic science that will have real effects on the industrial processes we count on each day," Pamela Jansma, dean of the UT Arlington College of Science said. "His previous success in the field has earned him the National Science Foundation's continuous support in unraveling complicated chemistry questions."
Dias new grant will also fund outreach and mentoring for high school students and teachers, as well as strengthening collaborative relationships with foreign universities.
The University of Texas at Arlington is a comprehensive institution of about 33,300 students and more than 2,200 faculty members in the heart of North Texas. It is the second largest school in The University of Texas System. Visit http://www.uta.edu to learn more.