Crystal structure of caesium hydrogen ( L )‐aspartate and an overview of crystalline compounds of aspartic acid with inorganic constituents

The crystal structure of the new polar compound caesium hydrogen ( L )‐aspartate, Cs(C 4 H 6 NO 4 ), (abbreviated: Cs( L ‐AspH)) was determined from single crystal X‐ray diffraction data; it comprises two crystallographically different L ‐AspH anions that are connected via caesium cations to form a three dimensional framework. The Cs ions are irregularly sevenfold [Cs1O 7 ] respectively eightfold [Cs2O 8 ] coordinated to all α– and β– carboxylate oxygen atoms. Cs( L ‐AspH) represents a novel structure type of its own, as do most compounds of ( L )‐aspartic acid with inorganic constituents. A brief summary of such structurally known aspartates is given. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)