Postsynthetic Metathesis in an All Organic Two-Dimensional Array Mediated by Hydrogen Bonding

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• 作者：Aina Mardia Akhmad Aznan ; A. P. Safwan ; Zanariah Abdullah ; Trupta Kaulgud ; Hadi D. Arman ; Matthew Mahindaratne ; L. E. McNeil ; Edward R. T. Tiekink
• 刊名：Crystal Growth & Design
• 出版年：2014
• 出版时间：November 5, 2014
• 年：2014
• 卷：14
• 期：11
• 页码：5794-5800
• 全文大小：379K
• ISSN：1528-7505

文摘

Cocrystallization of equimolar quantities of sulfathiazole (STL) with each of 1,4-diazabicyclo[2.2.2]octane (DABCO) and piperazine (PIP) resulted in facile formation of salts [DABCOH][STL_H] (1) and [PIPH][STL_H] (2), respectively. Crystallography shows the formation of aniline-N鈥揌路路路O(sulfonyl) hydrogen bonds between anions to form supramolecular undulating and zigzag layers, respectively, with the cations being connected to these by charge-assisted N鈥揌路路路N(thioazole) interactions. ¹H NMR, IR, and Raman spectroscopies as well as powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) confirmed salt formation. Solid state grinding competition experiments were monitored by PXRD. In a sequence of experiments where STL was coground with a molar equivalent of PIP and n equivalents of DABCO (with n increasing from 0.1 to 1.0 in 0.1 increments), preferential formation of 1 was observed. In related experiments where 2 was ground with an equimolar amount of DABCO, substitution of PIPH⁺ by DABCOH⁺ was evident; i.e., postsynthetic metathesis had occurred to about 70% for dry grinding. Quantitative yields were obtained in the case of liquid-assisted grinding (LAG) with a few drops of ethanol after 1.4 equiv of DABCO were added. These observations are primarily correlated with differences in aniline-N鈥揌路路路O(sulfonyl) hydrogen bonding that sustain the layers.