Investigating discontinuous X-ray irradiation as a damage mitigation strategy for [M(COD)Cl]₂ catalysts

Area of Science:

• Materials Science
• Chemistry
• Physics

Background:

• Intense X-ray sources present challenges due to radiation-induced sample damage.
• Mitigation strategies are crucial for robust data collection in X-ray experiments.
• The impact of X-ray-free dark periods on radiation damage is not well understood.

Purpose of the Study:

• To investigate the effect of dark periods on X-ray radiation damage in small-molecule catalysts.
• To explore the phenomenon of
• dark progression
• and its influence on damage accumulation.
• To provide insights into optimizing experimental parameters to minimize radiation damage.

Main Methods:

• Studied X-ray-induced changes in [Ir(COD)Cl]2 and [Rh(COD)Cl]2 catalysts.
• Utilized synchrotron powder X-ray diffraction (PXRD) and laboratory photoelectron spectroscopy (XPS).
• Varied the duration and introduction of X-ray-free dark periods during experiments.

Main Results:

• Dark periods can influence the progression of radiation damage, potentially exacerbating it.
• Distinct damage mechanisms affecting unit cells, molecular units, and chemical environments were identified.
• The duration of dark periods impacts the extent and nature of radiation-induced changes.

Conclusions:

• The strategy of introducing dark periods requires careful consideration due to potential
• dark progression
• .
• Understanding radiation damage dynamics under varying exposure regimes is essential.
• Informed experimental design is crucial for minimizing radiation damage in sensitive samples.