Molecules containing benzene are everywhere. They can brighten the displays of many of the household electronics in everyday use and are found in much of the medicine we take. Benzene was one of the earliest organic molecules discovered as chemistry was becoming a field and is ubiquitous for a reason--it's useful. But for chemists like Caleb Martin, assistant professor and researcher in Baylor chemistry, there’s always more to discover.
"There are very few compounds that have been discovered that can serve as a substitute for benzene," Martin said. "Our research is focused on developing new benzene analogues to diversify the library of molecules available for applications in pharmaceuticals and electronic devices."
If you have an organic light emitting diode (OLED) screen on your television or computer, you likely have a product that contains connected chains of benzene--the electrical current sent through the benzene compound creates the colored light. Much of the medicine you take is likely made up of compounds featuring benzene. The push to discover benzene substitutes comes from the universal desire to make things, Martin said, “more efficient, more cost-effective. Those are the main driving forces. For example, OLED devices can operate on less power. Some colors are very difficult to obtain. And there’s always a need for new drugs as we develop immunities and as natural resources used for producing current drugs become scarce, in addition to the many illnesses that lack effective treatments."
Martin and the students in his research group search for benzene substitutes by replacing carbon atoms in benzene with other atoms that, while different, allow benzene to maintain the same six-atom central ring. The substituted atoms change the distribution of electrons in the system, providing manipulated compounds that could lead to breakthroughs with a wide range of benefits.
"We see how small tweaks change the compound's properties and search for how we can exploit those unique properties for use in electronic devices and medicine. It is shocking with the utility of such a molecule that hardly any effective substitutes have been developed," Martin said. "The principles we use are simple, but a small modification can go a long way."