Cyclohexanethiol and 2,4-Dimethyl−3-thiapentane: Molecular Vibrations, Conformational Analyses, and Chemical Thermodynamic Properties

Abstract

Statistical thermodynamic treatments were made of the conformational energetics of the cyclohexanethiol and 2,4‐dimethyl−3‐thiapentane molecules. For cyclohexanethiol, there are 24 conformations that arise from the chair—skew‐boat and equatorial—axial equilibria of the frame and different orientations of the thiol group. The equatorial‐chair conformation is the most stable; the axial‐chair conformation has about 1.1 kcal/mole greater energy. For 2,4‐dimethyl−3‐thiapentane, six conformations could arise from different orientations of the isopropyl groups; however, only a d—l pair that involves no methyl—methyl interaction between the isopropyl groups has appreciable stability. Vibrational assignments needed for each compound were obtained by interpreting the molecular spectra for the vapor, liquid, and crystal states with the guidance of force‐constant calculations. Tables of the chemical thermodynamic properties were compiled.