Crystal structures of amino acids: from bond lengths in glycine to metal complexes and high-pressure polymorphs

After the discovery of X-ray diffraction by crystals, amino acids were among the first organic compounds to have their solid-state structures investigated. The Cambridge Structural Database now contains more than 3500 entries for α-amino acids alone. After a short introduction dealing with the early history of X-ray structure determination, this review provides a classification of amino acid structures, describes essential structural elements, especially hydrogen bonding preferences and coordination to metal ions, and considers recent investigations on phase transitions as the result of extreme temperatures or pressure.

自晶体X射线衍射现象被发现以来，氨基酸便是首批被开展固态结构研究的有机化合物之一。目前，剑桥结构数据库（Cambridge Structural Database）中仅α-氨基酸（α-amino acids）相关的条目便已超过3500条。本文先简要介绍了X射线结构解析的早期发展历程，随后对氨基酸的晶体结构进行分类，阐述了其核心结构特征——尤其是氢键偏好性及与金属离子的配位作用，并探讨了近期针对极端温度或压力诱导相变的相关研究。