Estimation of boiling points using density functional theory with polarized continuum model solvent corrections.

Area of Science:

• Computational Chemistry
• Physical Organic Chemistry

Background:

• Accurate prediction of boiling points is crucial for chemical process design and molecular property analysis.
• Existing methods often lack accuracy or applicability across a wide range of organic molecules.

Purpose of the Study:

• To develop a novel, empirical method for estimating the boiling points of organic molecules.
• To leverage density functional theory (DFT) calculations with polarized continuum model (PCM) solvent corrections for enhanced accuracy.

Main Methods:

• Boiling point estimation based on the sum of three contributions: effective surface area from structural formula, DFT-PCM solvation energy, and a term for planar aromatic molecules.
• Application to a diverse set of organic molecules containing up to ten elements (C, H, Br, Cl, F, N, O, P, S, Si).
• Validation using training and test datasets.

Main Results:

• High correlation between observed and calculated boiling points: R²=0.980 for the training set (317 molecules) and R²=0.979 for the test set (74 molecules).
• Successful application to molecules with boiling points ranging from -50 to 500 °C.
• Quantitative discussion of the impact of intramolecular hydrogen bonding on boiling point reduction.

Conclusions:

• The developed DFT-PCM based empirical method provides a robust and accurate approach for predicting organic molecule boiling points.
• The method demonstrates broad applicability across diverse organic structures and chemical functionalities.
• This computational tool can aid in the design and optimization of chemical processes and the prediction of molecular behavior.