Crystal structures of three β-halolactic acids: hydrogen bonding resulting in differing Z ′
Crystal structures of three β-halolactic acids: hydrogen bonding resulting in differing Z ′
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三种 β-卤代乳酸的晶体结构：氢键导致不同的 Z ∀2
DOI：
10.1107/s2053229622002856
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Skrabalak, Sara E.
中科院分区：
文献类型：
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作者：
Gordon, Matthew N.;Liu, Yanyao;Shafei, Ibrahim H.;Brown, M. Kevin;Skrabalak, Sara E.
测定了三种β-卤代乳酸的晶体结构，即β-氯代乳酸（系统名：3-氯-2-羟基丙酸，C3 H5 ClO 3）（I）、β-溴代乳酸（系统名：3-溴-2-羟基丙酸，C3 H5 BrO 3）（II）和β-碘代乳酸（系统名：2-羟基-3-碘丙酸，C3 H5 IO 3）（III）。发现每个晶体结构的不对称单元中的分子数（Z′）对于I和II是2个，对于III是1个，使得I和II是同构的，而III是唯一的。I和II的不对称单元中的分子之间的差异是由于醇基团与相邻分子的氢键的方向。分子堆积表明，每个结构具有分子间氢键和卤素-卤素相互作用的交替层。Hirshfeld表面和二维指纹图进行了分析，以进一步探讨这些结构的分子间相互作用。在I和II中，通过降低对称性以在不对称单元中采用两个独立的分子构象来实现能量最小化。
The crystal structures of three β-halolactic acids have been determined, namely, β-chlorolactic acid (systematic name: 3-chloro-2-hydroxypropanoic acid, C3H5ClO3) (I), β-bromolactic acid (systematic name: 3-bromo-2-hydroxypropanoic acid, C3H5BrO3) (II), and β-iodolactic acid (systematic name: 2-hydroxy-3-iodopropanoic acid, C3H5IO3) (III). The number of molecules in the asymmetric unit of each crystal structure (Z′) was found to be two for I and II, and one for III, making I and II isostructural and III unique. The difference between the molecules in the asymmetric units of I and II is due to the direction of the hydrogen bond of the alcohol group to a neighboring molecule. Molecular packing shows that each structure has alternating layers of intermolecular hydrogen bonding and halogen–halogen interactions. Hirshfeld surfaces and two-dimensional fingerprint plots were analyzed to further explore the intermolecular interactions of these structures. In I and II, energy minimization is achieved by lowering of the symmetry to adopt two independent molecular conformations in the asymmetric unit.