Dissociation energies of O-H, N-H, and S-H bonds in sulfur-containing antioxidants

• Published in: Petroleum chemistry Vol. 54; no. 2; pp. 142 - 153
• Main Authors: Denisov, E. T., Denisova, T. G.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.03.2014; Springer
• Subjects: Antioxidants; Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Sulfides; Sulfur; Telomerase; Thiols; Dissociation Energy; Aminophenol; Bond Dissociation Energy; Petroleum Chemistry; Peroxyl Radical
• ISSN: 0965-5441; 1555-6239
• DOI: 10.1134/S0965544114010034

The dissociation energies of O-H bonds ( D O-H ) of 48 phenol sulfides and N-H bonds ( D N-H ) of five amino sulfides were determined from experimental data. The dissociation energies of the bonds were estimated by the method of crossing parabolas from the kinetic data (the rate constants of reactions of peroxyl radicals with these antioxidants). The O-H, S-H, and N-H bond dissociation energies were determined for three hybrid antioxidants (two hydroxythiophenols and one aminophenol): D O-H = 335.9 kJ mol −1 and D S-H = 340.8 kJ mol −1 for 2-hydroxy-3,5-bis-(1′-phenylethyl)thiophenol, D O-H = 337.7 kJ mol −1 and D S-H = 344.2 kJ mol −1 for 3,5-bis-(1′-phenylethyl)-4-hydroxythiophenol, and D O-H = 338.6 kJ mol −1 and D N-H = 366.2 kJ mol −1 for 1-( N -phenylamino)-2-thiol-3-thio-(3′,5′-bis-di- tert -butyl-4′-hydroxyphenyl)-propane.