ラセミ混合物(コングロメレート)結晶生成における水素結合ネットワークの役割 Role of Hydrogen-Bond Network in the Fromation of a Conglomerate
X-ray crystallographic studies were carried out for conglomerate salts, racemic-compound salts, and enantiomerically pure salts of chiral primary amines with achiral mono-carboxylic acids. The crystal structures of the conglomerate salts revealed that these crystals can be regarded as being a supramolecular assembly of a characteristic columnar hydrogen-bond network, in which the ammonium cations and the carboxylate anions are aligned around a twofold screw axis (2<SUB>1</SUB>-column) . On the other hand, the crystal structures of the racemic-compound salts could be roughly classified into two types. One type is a crystal consisting of 2<SUB>1</SUB>columns; the other type is a crystal consisting of a different type of columnar hydrogen-bond network, in which the ammonium cations and the carboxylate anions are related by inversion centers (<I>i</I>-column) .These results suggest that both the formation and the assembly of 2<SUB>1</SUB>columns are essential in the formation of conglomerates for these salts.
日本結晶学会誌 38(6), 414-420, 1996-12-31
The Crystallographic Society of Japan