Novel carboxylic acid derivatives were synthesized, which allowed switching of the intramolecular distance between amide group and carboxylic oxygen atoms using E to Zphotoisomerization of the cinnamate framework. An intramolecular NHâ¯O hydrogen bond was formed in the Zcarboxylate compound not only in solution but also in the solid state. The pKa value of the carboxylic acid was lowered as a consequence of the E/Zphotoisomerization.
合成了新型羧酸衍生物,该衍生物可以利用肉桂酸酯骨架的 E 至 Z 光异构化来切换酰胺基团和羧基氧原子之间的分子内距离。 Z羧酸酯化合物不仅在溶液中而且在固态中都形成分子内NH-O氢键。由于 E/Z 光异构化,羧酸的 pKa 值降低。