Amino acid hydrogen oxalate quasiracemates – sulfur containing side chains
Amino acid hydrogen oxalate quasiracemates – sulfur containing side chains
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氨基酸草酸氢准外消旋体 — 含硫侧链
DOI：
10.1039/d1ce01214b
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发表时间：
2021
期刊：
影响因子：
3.1
通讯作者：
Wheeler, Kraig A.
中科院分区：
文献类型：
--
作者：
Wells, Russell G.;Sahlstrom, Katriel D.;Wheeler, Kraig A.
通过将三元组分（草酸氢）与氨基酸准对映体对共结晶，开发了准外消旋材料的新添加物，其中至少一个侧链 R 基团含有硫原子。在研究的八种准外消旋体中，六种表现出晶体堆积，其与外消旋对应物和现有准外消旋材料数据库中存在的预期中心对称排列截然不同。对这些结构的构象相似性（CCDC-Mercury 结构叠加）和每个准对映体对的反演对称程度（Avnir 连续对称测量）进行了定量评估。尽管准对映异构体成分存在差异，但这些结构表现出高度的同构结构，其中主要成分通过常见的 N+–H⋯O 和 O–H⋯O− 相互作用的复杂混合物组装而成。这些电荷辅助的氢键网络形成热力学上有利的晶体堆积，促进结构多样的准对映体组分的共结晶。
New additions to quasiracemic materials have been developed by cocrystallizing a ternary component – hydrogen oxalate – with pairs of amino acid quasienantiomers where at least one of the side-chain R groups contains a sulfur atom. Of the eight quasiracemates investigated, six exhibit crystal packing that drastically deviates from the expected centrosymmetric alignment present in the racemic counterparts and the extant database of quasiracemic materials. These structures were quantitatively assessed for conformational similarity (CCDC-Mercury structure overlay) and the degree of inversion symmetry (Avnir's Continuous Symmetry Measures) for each quasienantiomeric pair. Despite the variance in quasienantiomeric components, these structures exhibit a high degree of isostructurality where the principal components assemble by a complex blend of common N+–H⋯O and O–H⋯O− interactions. These charge-assisted hydrogen-bonded networks form thermodynamically favored crystal packing that promotes cocrystallization of a structurally diverse set of quasienantiomeric components.