Shenghur, Abraham; Weber, Kevin H.; Nguyen, Nhan D.; Sontising, Watit; Tao, Fu-Ming published the artcile< Theoretical Study of the Hydrogen Abstraction of Substituted Phenols by Nitrogen Dioxide as a Source of HONO>, Name: 2-Amino-3-methoxyphenol, the main research area is nitrogen dioxide hydrogen abstraction phenol nitrous acid formation.
The mild yet promiscuous reactions of nitrogen dioxide (NO2) and phenolic derivatives to produce nitrous acid (HONO) have been explored with d. functional theory calculations The reaction is found to occur via four distinct pathways with both proton coupled electron transfer (PCET) and hydrogen atom transfer (HAT) mechanisms available. While the parent reaction with phenol may not be significant in the gas phase, electron donating groups in the ortho and para positions facilitate the reduction of nitrogen dioxide by electronically stabilizing the product phenoxy radical. Hydrogen bonding groups in the ortho position may addnl. stabilize the nascent resonantly stabilized radical product, thus enhancing the reaction. Catechol (ortho-hydroxy phenol) has a predicted overall free energy change ΔG0 = -0.8 kcal mol-1 and electronic activation energy Ea = 7.0 kcal mol-1. Free amines at the ortho and para positions have ΔG0 = -3.8 and -1.5 kcal mol-1; Ea = 2.3 and 2.1 kcal mol-1, resp. The results indicate that the hydrogen abstraction reactions of these substituted phenols by NO2 are fast and spontaneous. Hammett constants produce a linear correlation with bond dissociation energy (BDE) demonstrating that the BDE is the main parameter controlling the dark abstraction reaction. The implications for atm. chem. and ground-level nitrous acid production are discussed.
Journal of Physical Chemistry A published new progress about Abstraction reaction enthalpy. 40925-69-7 belongs to class ethers-buliding-blocks, and the molecular formula is C7H9NO2, Name: 2-Amino-3-methoxyphenol.
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem