Investigating Additive Effects on α‑Glycine Growth through the Measurement of Facet Specific Growth Rates

Offiler, Caroline; Davey, Roger J.; Cruz-Cabeza, Aurora J.; Vetter, Thomas

Abstract

The presence of trace amounts of additives during crystal growth can have a significant impact on the physical properties of the crystallizing substrate (e.g., crystal morphology, purity, polymorphic phase, or growth kinetics). In this work, we report the growth of α-glycine crystals (α-gly) in the presence of a variety of diverse additives: two l-amino acids, two organic acids, α-iminodiacetic acid, and two chloride salts. Growth rate data from imaging, together with analytical techniques such as X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy, are used to observe which facet growth is impacted by the additive and to what extent. Relating these findings to the α-gly crystal structure provides explanations for the observed effects. Specifically, the growth inhibition of the (02̅0) facet α-gly in the presence of l-tryptophan and l-methionine shows how the prochirality of glycine results in two symmetrically equivalent facets growing at different rates. In the presence of malonic acid and salicylic acid, growth of the {011} facets is inhibited as a result of the interaction of deprotonated acids at the {011} surfaces. We find α-iminodiacetic acid to be an extremely effective inhibitor of α-gly, stopping the growth of both the {011} and {020} facets. We correlate the effectiveness of α-iminodiacetic acid to its structural similarity to gly, allowing it to easily block the growth of two α-gly facets. Finally, we observe the incorporation of the metal ions Fe(II), Cu(II), and Zn(II) into the {011} facets of α-gly. Interestingly, in the cases of Cu(II) and Zn(II), the incorporation of the metals into the α-gly lattice does not cause a noticeable change in the growth rates. The formation of coordination complexes containing the metal ions and glycine ligands allows for the observed incorporation of the metals into the α-gly lattice with limited disturbance to its crystal growth.

Citation

Offiler, C., Davey, R. J., Cruz-Cabeza, A. J., & Vetter, T. (2025). Investigating Additive Effects on α‑Glycine Growth through the Measurement of Facet Specific Growth Rates. Crystal Growth and Design, 25(5), 1644-1652. https://doi.org/10.1021/acs.cgd.5c00028

• Journal Article Type: Article
• Acceptance Date: Feb 5, 2025
• Online Publication Date: Feb 13, 2025
• Publication Date: Mar 5, 2025
• Deposit Date: Mar 14, 2025
• Publicly Available Date: Mar 14, 2025
• Journal: Crystal Growth & Design
• Print ISSN: 1528-7483
• Electronic ISSN: 1528-7505
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 25
• Issue: 5
• Pages: 1644-1652
• DOI: https://doi.org/10.1021/acs.cgd.5c00028
• Public URL: https://durham-repository.worktribe.com/output/3699811