Chemists Use IR Lasers to ProbeMolecular Interactions

MADISON, Wis., Feb. 15 -- A group of chemists from the University of Wisconsin-Madison has developed a new method for probing the molecular universe using infrared spectroscopy. The researchers use two infrared lasers, which are choreographed to focus on a small sample, to read the minute, telltale vibrations of molecules. These vibrations can identify molecules and can aid in determining how the different bonds within and between the molecules are connected.
As described in Physical Review Letters, the new technique allows chemists to detect the fine details of how molecules are connected, both internally and externally. According to UW-Madison chemist John C. Wright, this knowledge could shed light on a host of scientific questions, ranging from how some bacteria resist antibiotics to the steps involved in the weathering of soil.
The use of two infrared lasers to drive two different vibrational modes to find the interconnections within and between molecules promises a powerful new way to study biological systems, said Wright. He noted that the new technique essentially serves as the long-sought analog to two-dimensional nuclear magnetic resonance spectroscopy, a mature technology that uses magnetic fields and energy from certain radio frequencies to glean information from atoms and molecules.