Ultrafast electron diffraction from transiently aligned asymmetric top molecules: Rotational dynamics and structure retrieval

Ultrafast electron diffraction (UED) from aligned molecules in the gas phase has successfully retrieved structures of both linear and symmetric top molecules. Alignment of asymmetric tops has been recorded with UED but no structural information was retrieved. We present here the extraction of two-dimensional structural information from simple transformations of experimental diffraction patterns of aligned molecules as a proof-of-principle for the recovery of the full structure. We align 4-fluorobenzotrifluoride with a linearly polarized laser and show that we can distinguish between atomic pairs with equal distances that are parallel and perpendicular to the aligned axis. We additionally show with numerical simulations that by cooling the molecules to a rotational temperature of 1 K, more distances and angles can be resolved through direct transformations. (C) 2022 Author(s).

Automated summary

This study demonstrates the extraction of two-dimensional structural information from simple transformations of experimental diffraction patterns, leading to the recovery of the complete molecular structure. By aligning molecules with a linearly polarized laser, the distinction between atomic pairs parallel and perpendicular to the alignment axis can be made. Cooling the molecules to a low temperature allows for the resolution of more distances and angles through direct transformations.