Crystal structure of p-xylene@silicalite-1

Area of Science:

• Materials Science
• Crystallography
• Supramolecular Chemistry

Background:

• Silicalite-1 (SL-1) is a widely studied zeolite with a specific pore structure.
• Understanding guest molecule interactions within zeolite frameworks is crucial for catalysis and separation applications.

Purpose of the Study:

• To elucidate the precise arrangement of p-xylene molecules within the silicalite-1 framework.
• To determine the crystal structure of a highly loaded silicalite-1/p-xylene complex.

Main Methods:

• Single-crystal X-ray diffraction was employed to solve the crystal structure.
• The unit cell composition was determined to be Si24O48·2C8H10.

Main Results:

• The crystal structure of silicalite-1 with eight p-xylene molecules per unit cell was successfully solved.
• P-xylene molecules were observed to occupy two distinct locations within the SL-1 channels.
• One p-xylene molecule is situated at the intersection of sinusoidal and straight channels.
• The second p-xylene molecule is located in the center of a double ten-membered ring (10-MR) within the sinusoidal channel.

Conclusions:

• The study provides detailed structural insights into the host-guest interactions in the silicalite-1/p-xylene system.
• The findings contribute to the understanding of molecular packing and location within zeolite frameworks.
• This structural information can guide the design of zeolites for specific adsorption and catalytic processes.