Oxygenated fluorocarbons are routinely found in sampling of environmental soils and waters as a result of the wide spread use of fluoro and chloro fluoro carbons in heating fluids and solvents. Their influence on and to the environment is of concern! The thermochemical properties of these species are needed for understanding their stability and reactions in the environment and in thermal processes. Structures and thermochemical properties on the mono- to tri- fluorinated methanols, CH3-xFxOH, and methyl hydroperoxides, CH3-xFxOOH (1≤x≤3), are determined by CBS-QB3, CBS-APNO, and G4 calculations. The S°298 and Cp(T)’s (300 ≤ T/K ≤ 1500) from vibration, translation, and external rotation contributions are calculated based on the vibration frequencies and structures obtained from the B3LYP/6-31+G(d,p). density functional method. Potential barriers for the internal rotations are calculated at the same calculation method and hindered rotation contributions to S°298 and Cp(T)’s are calculated using direct integration over energy levels of the internal rotational potentials. Standard enthalpy of formation, ΔHf°298, (units in kcal mol-1) are: CH2FOOH (-83.7), CHF2OOH (-138.1), CF3OOH (-193.6), CH2FOOo (-44.9), CHF2OOo (-99.3), CF3OOo (-153.8), CH2FOH (-101.9), CHF2OH (-161.6), CF3OH (-218.1), CH2FOo (-49.1), CHF2Oo (-97.8), CF3Oo (-150.5), CH2Fo (-7.6), CHF2o (-58.8), CF3o (-112.6). Bond dissociation energies for the R-OOH, RO-OH, ROO-H, R-OOo, RO-Oo, R-OH, RO-H, R-Oo, and R-H bonds are determined and compared with methyl hydroperoxide to observe the trends from added fluoro- substitutions.

Thermochemical properties (ΔfH°(298), S°(298), Cp(T) ) and bond dissociation energies for fluorinated methanols and fluorinated methyl hydroperoxides: CH3-xFxOH and CH3-xFxOOH

252nd National Meeting (2016)

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