Predicting Cocrystallization Based on Heterodimer Energies: The Case of N,N鈥?Diphenylureas and Triphenylphosphine Oxide

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• 作者：Marina A. Solomos ; Cameron Mohammadi ; Jessica H. Urbelis ; Elizabeth S. Koch ; Rochelle Osborne ; Claire C. Usala ; Jennifer A. Swift
• 刊名：Crystal Growth & Design
• 出版年：2015
• 出版时间：October 7, 2015
• 年：2015
• 卷：15
• 期：10
• 页码：5068-5074
• 全文大小：446K
• ISSN：1528-7505

文摘

Diarylureas frequently assemble into structures with one-dimensional H-bonded chain motifs. Herein, we examine the ability of triphenylphosphine oxide (TPPO) to disrupt the H-bonding motif in 14 different meta-substituted N,N鈥?diphenylureas (mXPU) and form cocrystals; 1:1 mXPU:TPPO cocrystals were obtained in 9 of 14 cases examined (64% success rate). Cocrystals adopt five different lattice types, all of which show unsymmetrical H-bonded [R_{ass="stack">2}^{ass="stack">1}(6)] dimers between the urea hydrogens and the phosphine oxygen. Heterodimer (mXPU路路路TPPO) and homodimer (mXPU路路路mXPU) interaction energies, 螖E_int, calculated using density functional theory at the B3LYP/6-31G(d,p) level were used to rationalize the experimental results. A clear trend was observed in which cocrystals were experimentally realized only in cases in which the differences in heterodimer versus homodimer energy, 螖螖E_int, were greater than 鈭?.3鈥? kcal/mol. Although calculated interaction energies are a simplified measure of the system thermodynamics, these results suggest that the relative 螖螖E_int between heterodimers and homodimers is a good predictor of cocrystal formation in this system.