Thermochemical Properties of Triphenylalkanes and Tetraphenylmethane. Strain in Phenyl Substituted Alkanes

Abstract

The standard (p° = 0.1 MPa) molar enthalpies of sublimation H m° at the temperature T = 298.15 K for 1,1,2-triphenylethane, triphenylmethane, 1,1,1-triphenylethane, 1,1,1-triphenylbutane, and tetraphenylmethane were obtained from the temperature function of the vapor pressure measured in a flow system. Standard molar enthalpy of formation Δf H m°(cr) at the temperature T = 298.15 K was measured using combustion calorimetry for 1,1,1-triphenylbutane. Enthalpies of fusion of all compounds were measured by differential scanning calorimetry. These experimental results together with the data available from the literature were used for the estimation of strain enthalpies of phenyl substituted alkanes and for the improvement of group-contribution methodology.

Gas–solvent and water–solvent partition coefficients of the tetraphenyl compounds of group (IV)

“…A number of sets of equations have been reported. [21][22][23] These are in quite reasonable agreement and yield for log C g at 298 K values of À13.91, 21 À13.66, 22 and À13.60 23 and for the enthalpy of vaporization, DH o vap , at 298 K values of 153.1, 21 140.8 22 and 140.0 23 kJ mol À1 . We select the values of Kana'an.…”

Gas-Phase Heat of Formation Values for Buckminsterfullerene (C60), C70 Fullerene (C70), Corannulene, Coronene, Sumanene, and Other Polycyclic Aromatic Hydrocarbons Calculated Using Density Functional Theory (M06 2X) Coupled with a Versatile Inexpensive Group-Equivalent Approach

“…The experimental Δ f H ° g,298 values used for several PAHs in the test set were those that had been critically evaluated by Roux et al for which there is general agreement with regard to their accuracy. Other Δ f H ° g,298 values for compounds included in Test Set 2 were among those listed in the ATcT Tables, the NIST WebBook, Cox and Pilcher’s Thermochemistry of Organic and Organometallic Compounds , or Pedley et al’s Thermochemical Data of Organic Compounds and/or from references in the literature. − A detailed list of literature references for reference/experimental Δ f H ° g,298 values selected for use in the training set and the two test sets is provided in Table S1.…”

Interplay of thermochemistry and Structural Chemistry, the Journal (volume 22, 2011, issues 1–3) and the discipline

“…is endothermic by almost 40 kJ mol -1 , as found using the enthalpies of formation of tri and tetraphenylmethane presented in [102]. What is the corresponding value for the all silicon case-we must acknowledge that the enthalpy of formation of triphenylsilane remains unknown from the experimental literature.…”