Beauchamp Guy
Department of Chemistry, Cégep de l'Outaouais College, 333 Cité des Jeunes, Gatineau, Québec, Canada J8Z 6M4.
J Phys Chem A. 2008 Oct 23;112(42):10674-80. doi: 10.1021/jp8066603. Epub 2008 Oct 1.
This study explores via structural clues the influence of weak intermolecular hydrogen-halogen bonds on the boiling point of halogenated ethanes. The plot of boiling points of 86 halogenated ethanes versus the molar refraction (linked to polarizability) reveals a series of straight lines, each corresponding to one of nine possible arrangements of hydrogen and halogen atoms on the two-carbon skeleton. A multiple linear regression model of the boiling points could be designed based on molar refraction and subgroup structure as independent variables (R(2) = 0.995, standard error of boiling point 4.2 degrees C). The model is discussed in view of the fact that molar refraction can account for approximately 83.0% of the observed variation in boiling point, while 16.5% could be ascribed to weak C-X...H-C intermolecular interactions. The difference in the observed boiling point of molecules having similar molar refraction values but differing in hydrogen-halogen intermolecular bonds can reach as much as 90 degrees C.
本研究通过结构线索探究了分子间弱氢-卤键对卤代乙烷沸点的影响。86种卤代乙烷的沸点与摩尔折射度（与极化率相关）的关系图呈现出一系列直线，每条直线对应着氢原子和卤原子在二碳骨架上九种可能排列中的一种。可以基于摩尔折射度和亚组结构作为自变量设计沸点的多元线性回归模型（R(2) = 0.995，沸点标准误差为4.2℃）。鉴于摩尔折射度可解释约83.0%的观测沸点变化，而16.5%可归因于弱C-X...H-C分子间相互作用，对该模型进行了讨论。具有相似摩尔折射度值但氢-卤分子间键不同的分子，其观测沸点差异可达90℃之多。
