Competitor analysis of functional group H-bond donor and acceptor properties using the Cambridge Structural Database

Area of Science:

• Crystallography
• Computational Chemistry
• Supramolecular Chemistry

Background:

• Intermolecular interactions in crystals arise from competition between functional groups.
• Energetically favorable interactions are more likely to occur.
• Previous statistical analyses of H-bonding are limited by non-random distributions of donors and acceptors in crystal structures.

Purpose of the Study:

• To analyze intermolecular interactions in the Cambridge Structural Database (CSD) as outcomes of functional group competition.
• To rank functional group hydrogen-bonding (H-bonding) properties based on their competitive success in crystal structures.
• To compare these rankings with experimental data and predict properties for unmeasured groups.

Main Methods:

• Analysis of intermolecular interactions within the CSD.
• Application of paired comparison algorithms (specifically TrueSkill) to rank functional groups.
• Comparison of calculated H-bonding rankings with experimental solution-phase parameters (β).

Main Results:

• Functional group H-bonding properties were ranked based on their frequency of winning interactions in crystal structures.
• Rankings for H-bond acceptors showed good agreement with experimental solution-phase parameters (β).
• Insufficient data was available to corroborate rankings for H-bond donors.

Conclusions:

• Paired comparison analysis of CSD data provides a robust method for ranking H-bonding properties.
• The method accurately ranks H-bond acceptors and can predict properties for unmeasured groups.
• Further data is needed to validate H-bond donor rankings obtained through this approach.