Scientists have used ultra-high-speed X-ray pulses to make a high-resolution movie of a molecule undergoing structural motions. The analysis, revealed in Nature Chemistry, reveals the dynamics of the processes in unprecedented detail catching the excitation of an only electron in the molecule.
The ability to see molecular motions in actual-time gives insights into chemical dynamics processes that had been unthinkable just some decades ago, the researchers say, and should finally assist in optimizing reactions and designing new kinds of chemistry.
The work is a collaboration among chemists from Brown, investigators at SLAC National Accelerator Laboratory and theoretical chemists from the University of Edinburgh. The group was directed by Peter Weber, professor of chemistry at Brown.
For the research, the researchers appeared at the molecular motions that happen when the organic molecule N-methyl morpholine is excited by pulses of ultraviolet light. X-ray pulses from SLAC’s LCLS (Linac Coherent Light Source) had been used to take snapshots at completely different stages of the molecule’s dynamic response.
The x-rays scatter particularly patterns depending on the structure of molecules. These patterns are analyzed and used to reconstruct a shape of the molecule because the molecular motions unfold. That sample analysis was led by Haiwang Yong, a graduate student at Brown and the research’s co-lead writer.
The experiment revealed a particularly delicate reaction by which solely a single electron turns into excited, causing a distinct pattern of molecular vibrations. The researchers have been able to picture both the electron excitation and the atomic vibration in effective detail.
A very attention-grabbing side of the response, the researchers say, is that it is coherent—that means when teams of those molecules work together with light, their atoms vibrate in live performance with one another.