In Situ Investigations of Mechanochemical One-Pot Syntheses.

Area of Science:

• Materials Science
• Chemistry
• Physical Chemistry

Background:

• Mechanochemistry enables solvent-free synthesis and material processing.
• Understanding reaction thermodynamics and kinetics is crucial for optimizing mechanochemical processes.
• Real-time monitoring of structural changes and temperature is needed to elucidate reaction mechanisms.

Purpose of the Study:

• To develop and apply an in situ triple-coupled technique combining X-ray diffraction, Raman spectroscopy, and thermography.
• To investigate the reaction mechanisms of prototypical mechanochemical syntheses in real time.
• To correlate structural evolution with temperature changes during milling.

Main Methods:

• In situ triple coupling of synchrotron X-ray diffraction, Raman spectroscopy, and thermography.
• Real-time monitoring of mechanochemical milling reactions.
• Analysis of structural evolution, temperature development, and reaction kinetics.

Main Results:

• The study elucidated reaction mechanisms for cocrystal formation, Knoevenagel condensation, and manganese-phosphonate synthesis.
• Identified trends in temperature development during milling, influenced by heat of reaction and latent heat of crystallization.
• Detected solid and liquid intermediates and distinguished mechanical impact effects from temperature effects.

Conclusions:

• The combined technique provides crucial insights into mechanochemical reaction thermodynamics and kinetics.
• Real-time temperature monitoring is essential for understanding mechanochemical process control.
• The study successfully separated mechanical and thermal contributions to reaction outcomes.