Solvent and hydrogen confinement in molecular capsules-Hirshfeld surface and molecular simulation analysis

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Computational Chemistry

Background:

• Molecular capsules are supramolecular structures capable of encapsulating guest molecules.
• Understanding the behavior of guest molecules within these capsules is crucial for designing new materials.
• The specific complex [(chloroform)(6)@C-n-butylpyrogallol[4]arene)(6)] serves as a model system.

Purpose of the Study:

• To investigate the intermolecular interactions and orientation of solvent molecules within a molecular capsule.
• To explore the energetic favorability of incorporating additional guest molecules (hydrogen) into the capsule.
• To correlate computational findings with experimental Nuclear Magnetic Resonance (NMR) data.

Main Methods:

• Hirshfeld surface analysis to examine intermolecular contacts and guest molecule arrangement.
• Molecular simulations to predict energetically favorable configurations.
• Nuclear Magnetic Resonance (NMR) spectroscopy for experimental validation.

Main Results:

• Hirshfeld surface analysis provided detailed insights into the 'ordered' inner phase of the capsule.
• Molecular simulations indicated that adding 2-3 hydrogen molecules to the existing six solvent molecules is energetically favorable.
• The simulation results showed good correlation with experimental NMR studies.

Conclusions:

• The study elucidates the precise arrangement and interactions of solvent molecules within the molecular capsule.
• Incorporating additional hydrogen molecules is a thermodynamically viable modification for this capsule system.
• The combined computational and experimental approach validates the findings and offers a pathway for future capsule design.