A Computational Design of Covalently Bonded Mixed Stacking Cocrystals

Area of Science:

• Materials Science
• Computational Chemistry
• Molecular Engineering

Background:

• Traditional donor-acceptor mixed stacking cocrystals suffer from thermal and mechanical instabilities.
• Designing stable cocrystals with tunable electronic properties is crucial for molecular electronics.

Purpose of the Study:

• To computationally design a new class of covalently bonded donor-acceptor mixed stacking cocrystals.
• To investigate the influence of functional groups and bridging units on cocrystal stability and electronic properties.

Main Methods:

• Computational design of trisilasumanene frameworks functionalized with electron-donating and electron-withdrawing groups.
• Alternative stacking of donor and acceptor units connected by sp3- and sp-carbon chains.
• Density Functional Theory (DFT) calculations using B3LYP-D3/6-31+G(d) level of theory to determine electronic properties and stability.

Main Results:

• Covalently bonded cocrystals demonstrate improved thermal and mechanical stability compared to non-covalently bonded counterparts.
• Tunable bandgaps ranging from 1.50 to 3.50 eV achieved by modifying donor and acceptor groups.
• Predicted significantly enhanced electrical conductance based on the Yoshizawa model.
• Bridge length variations offer control over material porosity with minimal impact on bandgaps.

Conclusions:

• Covalently bonded mixed stacking cocrystals represent a promising strategy for overcoming stability limitations in molecular electronic materials.
• The designed cocrystals offer tunable electronic properties and enhanced conductance, suitable for various applications.
• Further experimental validation is encouraged to realize the potential of these novel materials.