Effect of substituent on the rate of reaction between 4Y-ArNH2 (Y = H, F, Cl, CH3, OCH3, NH2, N(CH3)2, CF3, CN, NO2) with CH3OO in the gas phase

Effect of substituent (Y), including halogen (F and Cl), electron donating (ED) and electron withdrawing (EW) group on the thermoparameters and kinetic behavior of reactions between 4Y-ArNH2 and CH3OO center dot was computationally studied using density functional theory (DFT) at M05-2X/6-311++G(d,p) method in combination with the transition state theory (TST) in Eyringpy program. Based on the three mechanisms of reaction between 4Y-ArNH2 and CH3COO center dot , namely the hydrogen transfer (HAT/PCET), single electron transfer - proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET), the effects on the thermoparameters involved in these mechanisms were investigated. ED group reduces the bond dissociation energy (BDE) and ionization energy (IE) then also increases the rate of hydrogen transfer reaction of 4Y-ArNH2 and CH3OO center dot Hydrogen atom transfer reaction of ArNH2 with CH3OO center dot at 298.15 K in the gas phase preferably takes place via PCET with the rate constant k(PCET) of 1.19x10(-19) cm(3).molecule(-1).s(-1) is higher than that of k(HAT) of 2.19x10(-20) cm(3).molecule(-1).s(-1). The rate constants of all 4Y-ArNH2 + CH3OO center dot reactions were also reported and PCET mechanism is dominated with the branching ratio (gamma;%) ranging from 73 % to 95 %.

Automated summary

The effect of substituents (Y), including halogen (F and Cl), electron donating (ED), and electron withdrawing (EW) groups, on the thermoparameters and kinetic behavior of reactions between 4Y-ArNH2 and CH3OO center dot was computationally studied. It was found that the electron donating group (ED) reduces the bond dissociation energy (BDE) and ionization energy (IE), and increases the rate of hydrogen transfer reaction of 4Y-ArNH2 and CH3OO center dot.