Resolving Alternative Organic Crystal Structures using Density Functional Theory and NMR Chemical Shifts

Widdifield, Cory; Farrell, James; Cole, Jason; Howard, Judith; Hodgkinson, Paul

Abstract

Alternative (‘repeat’) determinations of organic crystal structures deposited in the Cambridge Structural Database are analysed to characterise the nature and magnitude of the differences between structure solutions obtained by diffraction methods. Of the 3132 structure pairs considered, over 20% exhibited local structural differences exceeding 0.25 Å. In most cases (about 83%), structural optimisation using density functional theory (DFT) resolved the differences. Many of the cases where distinct and chemically significant structural differences remained after optimisation involved differently positioned hydroxyl groups, with obvious implications for the correct description of hydrogen bonding. 1H and 13C chemical shifts from solid-state NMR experiments are proposed as an independent methodology in cases where DFT optimisation fails to resolve discrepancies.

Citation

Widdifield, C., Farrell, J., Cole, J., Howard, J., & Hodgkinson, P. (2020). Resolving Alternative Organic Crystal Structures using Density Functional Theory and NMR Chemical Shifts. Chemical Science, 11(11), 2987-2992. https://doi.org/10.1039/c9sc04964a

• Journal Article Type: Article
• Acceptance Date: Feb 10, 2020
• Online Publication Date: Feb 24, 2020
• Publication Date: Mar 21, 2020
• Deposit Date: Feb 11, 2020
• Publicly Available Date: Apr 2, 2020
• Journal: Chemical Science
• Print ISSN: 2041-6520
• Electronic ISSN: 2041-6539
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Issue: 11
• Pages: 2987-2992
• DOI: https://doi.org/10.1039/c9sc04964a
• Public URL: https://durham-repository.worktribe.com/output/1308514