Department of Organic Chemistry A. Mangini, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy.
Org Lett. 2010 May 21;12(10):2326-9. doi: 10.1021/ol100683u.
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.
对于有机硫属元素取代基的 ED/EW 特性及其对酚类化合物中 O-H 键离解焓 (BDE) 的贡献，人们知之甚少。本研究通过电子顺磁共振 (EPR)、红外 (IR) 和计算方法制备并研究了一系列邻位和对位 (S、Se、Te)R 取代的苯酚。取代基使对位的 O-H BDE 降低了 >3 kcal/mol，而由于氢键（约 3 kcal/mol）与 O-H 基团的相互作用，邻位效应则较为温和。
