Reconciliation of Experimental and Computed Thermodynamic Properties for Methyl-Substituted 3-Ring Aromatics. Part 2: 3 Methylphenanthrene

Published

March 1, 2022

Author(s)

Andrei F. Kazakov, Eugene Paulechka, Robert D. Chirico

Abstract

Measurements leading to the calculation of thermodynamic properties in the ideal-gas state for 3-methylphenanthrene (Chemical Abstracts registry number [832-71-3]) are reported. Experimental methods were adiabatic heat-capacity calorimetry, differential scanning calorimetry (d.s.c.), comparative ebulliometry, inclined-piston manometry, vibrating-tube densitometry, and oxygen bomb calorimetry. The critical temperature, critical pressure, and critical density were estimated based on these measurements. Molar thermodynamic functions for the condensed and ideal-gas states were derived from the experimental results. Statistical calculations were performed based on molecular geometry optimization and vibrational frequencies using B3LYP hybrid density functional theory with the def2-QZVPD basis set. Differences between computed and experimentally derived ideal-gas entropies are larger than the experimental uncertainties, but good accord is achieved if the two lowest-frequencies vibrational modes are assumed to be coupled, as was found for 9-methylanthracene in Part 1 of this pair of articles. The enthalpy of formation for 3-methylphenanthrene in the ideal-gas phase was computed with an atom-equivalent based protocol described recently, and excellent agreement with the experimental value is shown. Experimental results are compared with literature values, where possible.

Citation

Journal of Chemical and Engineering Data

Volume

67

Issue

8

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.jced.1c00908

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Keywords

computational chemistry, critical properties, density, enthalpy of formation, entropy, heat capacity, ideal-gas properties, 3-methylphenanthrene, vapor pressure

Citation

Kazakov, A. , Paulechka, E. and Chirico, R. (2022), Reconciliation of Experimental and Computed Thermodynamic Properties for Methyl-Substituted 3-Ring Aromatics. Part 2: 3 Methylphenanthrene, Journal of Chemical and Engineering Data, [online], https://doi.org/10.1021/acs.jced.1c00908, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933618 (Accessed October 7, 2025)