Molecular Recognition and Shape Studies of 3- and 4-Substituted Diarylamide Quasiracemates
Molecular Recognition and Shape Studies of 3- and 4-Substituted Diarylamide Quasiracemates
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DOI：
10.3390/cryst11121596
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发表时间：
2021-12
期刊：
影响因子：
2.7
通讯作者：
Alicia Brandt;Derek J. Boyle;Jacob P. Butler;Abigail R. Gillingham;Scott E. Penner;Jacqueline M. Spaniol-Jacqueline-M
中科院分区：
文献类型：
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作者：
Alicia Brandt;Derek J. Boyle;Jacob P. Butler;Abigail R. Gillingham;Scott E. Penner;Jacqueline M. Spaniol-Jacqueline-M
制备了由3-取代和4-取代手性二芳酰胺分子框架构建的准自由基材料家族，其中施加的官能团差异系统地从H到CF3-9不等，每个异构体框架的独特组分。利用所有可能的外消旋和准消旋组合，通过热阶段热显微观察熔体的共结晶，探索了准消旋体形成的结构边界。这些体系的晶体结构和晶格能（差示扫描量热法和晶格能计算）表明，准对映体成分的组织具有近反转对称性，晶格能量学与外消旋体非常相似。本研究还使用基于硅定向的方法比较了准对映体对的形状空间，以近似分子形状的差异，并为准对映体预测提供了诊断工具。将这些结果与我们最近对相关2-取代二芳基酰胺准羧酸盐的报告进行比较，表明官能团位置可以对准羧酸行为产生显着影响，并为更完整的形状空间提供关键见解，这对于定义分子识别过程至关重要。
Families of quasiracemic materials constructed from 3- and 4-substituted chiral diarylamide molecular frameworks were prepared, where the imposed functional group differences systematically varied from H to CF3–9 unique components for each isomeric framework. Cocrystallization from the melt via hot stage thermomicroscopy using all possible racemic and quasiracemic combinations probed the structural boundaries of quasiracemate formation. The crystal structures and lattice energies (differential scanning calorimetry and lattice energy calculations) for many of these systems showed that quasienantiomeric components organize with near inversion symmetry and lattice energetics closely resembling those found in the racemic counterparts. This study also compared the shape space of pairs of quasienantiomers using an in silico alignment-based method to approximate the differences in molecular shape and provide a diagnostic tool for quasiracemate prediction. Comparing these results to our recent report on related 2-substituted diarylamide quasiracemates shows that functional group position can have a marked effect on quasiracemic behavior and provide critical insight to a more complete shape space, essential for defining molecular recognition processes.