Absence of halogen...halogen interactions in chlorotrimethylsilane polymorphs

Area of Science:

• Solid-state chemistry
• Crystallography
• Materials science

Background:

• Understanding crystal structures under extreme conditions is crucial for materials science.
• Chlorotrimethylsilane ((CH3)3SiCl) is a relevant compound for studying intermolecular interactions.

Purpose of the Study:

• To determine the crystal structures of chlorotrimethylsilane at high pressures.
• To investigate the relationship between low-temperature and high-pressure polymorphs.
• To analyze the factors influencing molecular packing and intermolecular contacts.

Main Methods:

• In situ pressure-freezing technique to stabilize high-pressure phases.
• X-ray diffraction to determine crystal structures.
• Analysis of unit-cell dimensions and molecular arrangements.

Main Results:

• Two-dimensional isostructurality was observed between low-temperature and high-pressure phases of (CH3)3SiCl.
• Unit-cell dimensions showed striking similarities across polymorphs.
• Absence of short Cl...Cl contacts was noted and rationalized.

Conclusions:

• The packing patterns and comparable energies of van der Waals forces, including halogen...halogen interactions, dictate the observed structures.
• The study provides insights into the behavior of organosilicon compounds under pressure.