Separation and Structure of Chiral S-Malic Acid Hydrate

• 来源期刊: 中国化学（英文版）
• 年，卷（期）: 2002,（4）
• 页码范围: 395-398
• 页数: 4页
• 语种: 英文

摘要

Crystals of the chiral malic acid hydrate ( C4H6O5@H2O ) were unexpectedly obtained from an ethanol ethanol/water solution containing racemic D,L-malic acid and L-asparagine. The crystal belongs to orthorhombic space group P21 21 21 with cell dimensions of a=0.5576(1), b=0.9818(2), c=1.1793(2) nm, V=0.9455(2) nm3, Z=4, μ(Mo Kα) =0.152 mm-1, F(000) =320, Dc= 1.565 g@cm-3, R =0.051, wR =0.136 for 657 observed reflections [I＞2σ(I)]. The significant difference in bond distances for carboxyl groups suggests that the crystal consist of malate anion and protonized crystalline water. This is a report for direct separation of racemic mixture, i.e., without the formation of a molecular complex of raceme with a chiral separating reagent.