Thymine hydrate (TH) is a classic hydrate system in which water molecules are highly confined in linear one-dimensional channels. Here, we describe our efforts to tune the channel volume by preparing isomorphous mixed crystals with increasing concentrations of uracil (Ur) and 5-ethyluracil (EUr), molecular analogues with slightly smaller and larger volumes, respectively. Solutions with up to 20 mol % Ur successfully yielded isomorphous mixed crystals of TH-Ur x in phase-pure form, though analysis of the mixed crystal compositions indicated that only ∼46% of the Ur available in the initial growth solution was proportionately included in the host lattice. The thermal stability of the mixed TH-Ur x material was significantly altered, with a greater fraction of water loss occurring at low temperature compared to the pure hydrate phase. Isomorphous mixed crystals with EUr substitutions, TH-EUr x , were successfully prepared from solutions with 5–10 mol % EUr, although the fraction of EUr included was much lower (∼13–36%) than Ur. As the concentration of EUr in the growth solution increased to 15–20 mol %, an unexpected mixed composition anhydrate emerged as the dominant crystallization product. Although packing fraction estimates suggested that higher EUr substitution levels in the hydrate were theoretically possible, the formation of the mixed anhydrate presented a more favorable route to a dense material phase.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.