Twisted perylene stereodimers reveal chiral molecular assembly codes.
Twisted perylene stereodimers reveal chiral molecular assembly codes.
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DOI：
10.1021/ja7111959
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发表时间：
2008-06
影响因子：
15
通讯作者：
Wei Wang;Andrew D Shaller;Alexander D. Q. Li
中科院分区：
文献类型：
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作者：
Wei Wang;Andrew D Shaller;Alexander D. Q. Li
独特的苝非对映体的线性和环状二聚体的合成从扭曲的苝单体，揭示了π堆积立体异构赋予特定的分子间自组装和分子内折叠。只有纯手性扭曲的四氯苝单体通过协同反应环化，形成纯手性非对映体。异手性四氯苝单体通过逐步反应得到线性异手性二聚体，其与线性纯手性二聚体平衡。线性纯手性二聚体环化以产生相同的环状纯手性非对映异构体。这些结果表明，同手性和异手性自组装是两种不同的分子密码，指导两种特定的化学途径。纯手性环状二聚体在-20 ° C下保持异构纯，但在室温下可相互转化为杂手性环状二聚体内消旋化合物。通过HPLC容易地分离非对映异构体。当由疏溶剂力驱动时，使用亚磷酰胺化学从相同的扭曲单体合成的可折叠线性二聚体折叠成同二聚体和异二聚体，证实了由二萘嵌苯手性决定的固有分子密码，最终测量弱π堆叠力，并指导自组装和折叠。
Unique perylene diastereomeric linear and cyclic dimers were synthesized from twisted perylene monomers, revealing that pi-stacking stereoisomerism imparted specific intermolecular self-assembly and intramolecular folding. Only the homochiral twisted tetrachloroperylene monomers cyclized via a cooperative reaction, forming the homochiral diastereomers. The heterochiral tetrachloroperylene monomers proceeded through a stepwise reaction and yielded a linear heterochiral dimer, which equilibrated with the linear homochiral dimers. The linear homochiral dimers cyclized to produce the same cyclic homochiral diastereomers. These results demonstrated that homochiral and heterochiral self-assemblies were two distinct molecular codes, directing two specific chemical pathways. The homochiral cyclic dimers remain isomerically pure at -20 degrees C but can be interconverted to the heterochiral cyclic dimer meso compound at room temperature. The diastereomers were readily separated by HPLC. While driven by solvophobic forces, foldable linear dimers synthesized from the same twisted monomers using phosphoramidite chemistry folded into homodimer and heterodimer, confirming the inherent molecular codes, which were dictated by the perylene chirality, ultimately gauged the weak pi-stack forces, and directed self-assembly and folding.