Abstract In the early 19th century, scientists gradually discovered that substances composed of the same elements were not unique; substances with identical elemental compositions could also exhibit different properties. The concept of “isomerism” emerged from the debates surrounding the compositional analysis of silver cyanate and silver fulminate. Since then, scientists began to focus on the modes of connection among atoms within molecules. With the introduction of the carbon tetravalence theory and the tetrahedral carbon configuration, the theoretical framework of stereochemistry was progressively established. The discovery of isomerism phenomena such as optical isomerism and cis-trans isomerism further advanced the development of stereochemistry. The establishment and evolution of the concept of isomerism reflect the transformation of chemistry from a descriptive, empirical science into a rational, predictive modern science.
LIN Lan-Qing, WEI Zhao, QIU Chen-Xin, ZHOU Mi. Discovery of Isomerism and Development of Concept of Isomers[J]. Chinese Journal of Chemical Education, 2026, 47(9): 119-125.
