Using the Intermolecular Interaction Index to Understand the Change in Boiling Points of Alkanes
Chao‐Tun Cao, Chao-Tun Cao, Chenzhong Cao, Chenzhong Cao · Journal of Chemical Education · 2023
By organizing an extracurricular seminar, based on the analysis of the intermolecular dispersion action in normal alkanes, a new topological index (named “Intermolecular Interaction Index (IMI)”) was proposed to express the intermolecular dispersion force. The IMI has an excellent linear relationship with the boiling point ( T b ) of normal alkanes containing carbon atoms C 2 –C 40 (standard error only 0.87 K). For T b of branched alkane isomers, only the addition of a parameter ΔAOEI (“average odd–even index difference”) is needed to establish the correlation equation. The seminar activity promotes students’ ability for molecular structure–property reasoning and provides students with a preliminary understanding of the molecular graph, topological index, and principle of development of quantitative structure–property relationship (QSPR) models.