One-of-a-kind spectrometer reads vibrations between atoms to find structures of molecules:
By measuring the vibrations between atoms using femtosecond-long laser pulses, the Rice lab of chemist Junrong Zheng is able to discern the positions of atoms within molecules without the restrictions imposed by X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) imaging.
The technique can capture the structure of molecules at room temperature or very low or high temperatures and in many kinds of samples...
"The atoms in every molecule are always vibrating, and each bond between atoms vibrates at a certain frequency, and in a certain direction," he said. "We found that if we can measure the direction of one vibration and then another, then we can know the angle between these two vibrations – and therefore the angle between the bonds."
He said the researchers begin with the chemical formula and already know, through Fourier transform infrared spectroscopy, how many vibrational frequencies are contained in a given molecule. "Then we measure each vibrational mode, one by one. Once we get all the cross-angles, we can translate this to a model," he said.