Filtern
Erscheinungsjahr
- 2021 (3) (entfernen)
Dokumenttyp
- Posterpräsentation (2)
- Vortrag (1)
Sprache
- Englisch (3)
Referierte Publikation
- nein (3)
Schlagworte
- High Pressure (2)
- Mechanochemistry (2)
- Cocrystal (1)
- Density Functional Theory (1)
- Density-functional theory (1)
- Energy (1)
- Fluorine Interaction (1)
- Hexafluorobenzen (1)
- Polymorph (1)
Organisationseinheit der BAM
- 6 Materialchemie (3)
- 6.3 Strukturanalytik (3)
Eingeladener Vortrag
- nein (1)
The reactivity of organic solids under mechanochemical conditions remains very little understood, though many processes have been found empirically. Importantly, it is not well understood how mechanical treatment induces experimentally observed chemical transformations, and if the elevated pressures arising at the point of impact can play a role in the transformation. To understand this aspect of the mechanochemical reactions, the same compounds need to be explored under high pressure conditions. As a model system, we considered the reaction between the bis(4-chlorophenyl) disulfide and bis(2-nitrophenyl) disulfide. A powder mixture of these two compounds is known to undergo a disulfide exchange reaction under ball milling conditions. Using a combination of X-ray powder diffraction and dispersion-corrected density functional theory calculations, we investigated how this binary solid system behaves at elevated pressures and whether pressure alone can explain its mechanochemical reactivity.
This work aims to investigate the role of F-F and F-π interactions in dictating structural and mechanical properties, through a combination of X-ray powder diffraction and dispersion-corrected density functional. As no benchmarking data exist for F-dominating organic system, we first assess how different functionals affect the mechanical properties of the material.
Control of ball milling conversions is required before the full potential of mechanochemical processing can be realized. It is well known that many parameters affect the outcome of mechanochemical polymorphism, but the energy of ball milling itself is often overlooked. We show here how this parameter alone can exert a significant influence on the polymorphic outcome of ball mill grinding by allowing the selective isolation of two polymorphic forms in their pure form under the same grinding conditions. Furthermore, we show how apparent mechanochemical equilibria can be deceptive. Our results clearly demonstrate the need for careful design and interpretation of ball milling experiments beyond current thinking.