Organochalcogen substituents in phenolic antioxidants.
Little is known about the ED/EW character of organochalcogen substituents and their contribution to the O-H bond dissociation enthalpy (BDE) in phenolic compounds. A series of ortho- and para-(S,Se,Te)R-substituted phenols were prepared and investigated by EPR, IR, and computational methods. Substituents lowered the O-H BDE by >3 kcal/mol in the para position, while the ortho-effect was modest due to hydrogen bonding ( approximately 3 kcal/mol) to the O-H group.
Amorati
Riccardo
R
Department of Organic Chemistry A. Mangini, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy.
Pedulli
Gian Franco
GF
Valgimigli
Luca
L
Johansson
Henrik
H
Engman
Lars
L
D000975:Antioxidants / Q000138:chemical synthesis* / Q000737:chemistry; D018011:Chalcogens / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013816:Thermodynamics
D000975:Antioxidants; D018011:Chalcogens; D010636:Phenols