The values of ΔfHo298.15 and So298.15 of the radicals formed by the abstraction of H atom from the p‐Benzylphenol and Dimethyl Phthalate

In the present work, the thermochemical properties of the radicals (Y j ), formed by abstraction of H atom from Dimethyl Phthalate (o‐Ph(C(O)OCH 3 ) 2 ) and p‐Benzylphenol (p‐PhCH 2 PhOH), are determined at the B3LYP/6‐311++G(d,p) (j = 1), M06‐2X/6‐311++G(d,p) (j = 2), and RO/CBS‐4 M (j = 3 and 4) levels of theory. Their calculated values of H o 298.15 (Y j , CALC) are used for the determination of thermochemistry of atomization (Δ r H o 298.15 (Y j ,CALC) atom ) and homodesmotic (Δ r H o 298.15 ((R Yi ) j ,CALC) REAC ) reactions of considered radicals. The reported calibration dependencies are used for the correction of calculated values and determination of the most consistent and accurate values of Δ f H o 298.15 and Δ f G o 298.15 . It is found that o‐CH 3 OC(O)PhC(O)OCH 2 ∙ (1C), p‐PhC ∙ HPhOH (1D) and p‐PhCH 2 PhO ∙ (3D) are the most thermochemically stable structures. The intersection of reported 3SE j (= 3σ j ) intervals of Δ f H o 298.15 (1C j ,CORR) atom of atomization results the value of Δ f H o 298.15 (1C,CORR) MEAN = −405.1 ± 1.3 kJ/mol (±3SE Y = 3σ Y ), while, the most accurate values of Δ f H o 298.15 (1D and 3D,CORR) REACMEAN = 114.7 ± 0.4 and 135.8 ± 5 kJ/mol (± 3SE YREAC = 3σ YREAC ) are determined using the values Δ f H o 298.15 ((R Yi ) j ,CORR) REAC of homodesmotic reactions. The values of Δ f G o 298.15 , determined using the values of Δ f H o 298.15 and S o 298.15 of these radicals, demonstrate that the exothermic reaction (17) HO 2 ∙ + p‐PhCH 2 PhOH → H 2 O 2 + p‐PhC ∙ HPhOH (–22.9 kJ/mol) is thermochemically more favorable than the reaction (19) HO 2 ∙ + p‐PhCH 2 PhOH → H 2 O 2 + p‐PhCH 2 PhO ∙ (–1.8 kJ/mol). However, the value of k T ( 17 ) = 1.63 × 10 –14 ( T /298.15) 3.6 e (‐6282/ T ) , calculated using the VTST, is kinetically more favorable at elevated temperatures, while, the reaction (19) ( k T ( 19 ) = 1.04×10 –16 ( T /298.15) 2.17 e (–5207/ T ) ) is more important at T < 200 K. The thermochemical properties of these radicals, as well as the calculated rate constants of their formation in reactions of HO 2 ∙ radicals with p‐Benzylphenol, are reported for the first time.