A Computationally Inspired Investigation of the Solid Forms of (R)-1-Phenylethylammonium-(S)-2-phenylbutyrate
A Computationally Inspired Investigation of the Solid Forms of (R)-1-Phenylethylammonium-(S)-2-phenylbutyrate
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DOI：
10.1002/chir.20761
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发表时间：
2010-05-05
期刊：
影响因子：
2
通讯作者：
Jones, Alan G.
中科院分区：
文献类型：
--
作者：
Antoniadis, Constantinos D.;D'Oria, Emiliana;Jones, Alan G.
在计算晶格能景观（其预测应该存在更稳定、更致密形式的（R）-1-苯基乙基铵-（S）-2-苯基丁酸盐）之后，从一系列溶剂中进行结晶以搜索其他多晶型物并研究已知P4（1）结构可能是水合物的可能性。广泛的结晶实验，从广泛的溶剂得到细针或微晶样品。通过粉末X射线衍射重新确定P4（1）结构定位所有质子，并结合其他实验和计算证据表明该结构是无水的。另外两种形式的证据是与I型的混合物。这些包括斜方晶形式，可能是Z' = 3多晶型物，以及从二氯甲烷溶液中作为次要组分获得的另一种尚未鉴定的形式。然而，这两种形式相对于形式I（P4（1））似乎是亚稳定的，因此形式I可能是在环境条件下可以从溶液中结晶的最稳定的形式。对非对映体盐体系（R）-1-苯基乙基铵-（R/S）-2-苯基丁酸盐中不易结晶的成员的固态行为的测定对解释其理想拆分行为的理论建模提出了挑战。Chirality 22：447-455，2010. (C)2009威利-利斯公司
Following the computation of a lattice energy landscape which predicted that there should be more stable, denser forms of (R)-1-phenylethylammonium-(S)-2-phenylbutyrate, crystallizations from a range of solvents were performed to search for other polymorphs and investigate the possibility that the known P4(1) structure could be a hydrate. Extensive crystallization experiments from a wide range of solvents gave fine needles or microcrystalline samples. A redetermination of the P4(1) structure by powder Xray diffraction located all protons, and in conjunction with other experimental and computational evidence showed that the structure was anhydrous. Evidence for two additional forms was found as mixtures with form I. These include an orthorhombic form, possibly a Z' = 3 polymorph, and another as yet unidentified form obtained as a minor component from dichloromethane solution. However, both these forms appear to be metastable with respect to form I (P4(1)), which is therefore probably the most thermodynamically stable form that can be crystallized from solution under ambient conditions. This determination of the solid state behavior of the less readily crystallized member of the diastereomeric salt system (R)-1-phenylethylammonium-(R/S)-2-phenylbutyrate provides a challenge to the theoretical modeling to explain its ideal resolution behavior. Chirality 22:447-455, 2010. (C) 2009 Wiley-Liss, Inc.