双取代铵氧化物(R2HNO)与双取代羟胺(R2NOH)的相互转换机制的理论研究－取代基的电负性和立体效应影响

At the B3LYP/6-311++G(d, p) level, we studied the conversion mechanism between the double-substituted ammonium oxides(R2HNO) and double-substituted hydroxylamines (R2NOH) with R=NH2, N(CH3)2, N(CH2CH3)2, N[C(CH3)3]2, OH, OCH3, OCH2CH3 and OC(CH3)3. It was shown that the thermodynamic and kinetic stability of the double-substituted ammonium oxides R2HNO are co-controlled by the electronegativity and steric effects. Amongst, the thermodynamic stability of amino-substituted species is dominated by steric effect, whereas that of the alkoxy-substituted species is dominated by electronegativity. The kinetic stability of both amino- and alkoxy-substituted species is mainly influenced by electronegativity.