Quantitative description of structural effects on melting points of substituted alkanes

作者：Marvin Charton, Barbara I. Charton · 发表于：Journal of Physical Organic Chemistry · 年份：1994 · DOI：10.1002/poc.610070406 · 被引用次数：43 · 研究领域：Chemical Thermodynamics and Molecular Structure、Analytical Chemistry and Chromatography、Adsorption, diffusion, and thermodynamic properties of materials

Abstract Structural effects on the melting points of substituted alkanes, both branched and unbranched, ranging in length from 1 to 19 carbon atoms, were successfully correlated with a variant of the intermolecular force equation which included a variable capable of accounting for the packing energy contribution of the alkyl group. The final data set had 366 data points. The regression equation obtained accounted for 91·85% of the variance of the data with a standard error of 17·9 K. Twenty‐nine data points could not be included in the correlation; nine of these are carboxamides. The contributions of the polar variables are slightly larger than those of the nonpolar variables while the contribution of structural variation in the substituent is greater than that in the alkyl group. It will be necessary to determine appropriate values of the packing parameter if compounds with chains longer than 20 carbon atoms are to be included in the model.