Abstract This paper is based on the Valence Shell Electron Pair Repulsion theory and hybrid orbital theory from the high school chemistry elective course 2,combined with Lewis structure theory from university inorganic chemistry. By calculating the sum of the σ-bond electrons and lone pair electrons of the central atom,a criterion is proposed to determine whether AXnm-type species possess delocalized π bonds. Furthermore,the number of electrons provided by various types of delocalized π bonds to satisfy the octet rule is clarified. Through a series of deductions and derivations,a simplified formula for calculating the number of electrons in delocalized π bonds is established. This method does not require the use of molecular structure diagrams; the type of delocalized π bond can be directly determined solely through formulaic calculation. By integrating fundamental chemical concepts with mathematical thinking to address complex chemical problems,this approach helps promote the development of students’ evidential reasoning and model-based cognition abilities,effectively enhancing their core competencies in chemistry.
ZHENG Mu-Yan. Novel Method for Analyzing Delocalized π Bonds Independent of Spatial Configuration: From Lewis Structures to Electron Count[J]. Chinese Journal of Chemical Education, 2026, 47(11): 97-101.
