Structures,Electron Affinities,and Harmonic Vibrational Frequencies of the Simplest Alkyl Peroxyl Radicals and Their Anions

摘要

The molecular structures and electron affinities of the R-OO/R-OO~-(R=CH3,C2H5,n-C3H7,n-C4H9,n-C5H11,i-C3H7,t-C4H9)species have been determined using seven different density functional or hybrid Hartree-Fock density functional methods.The basis set used in this work is of double-zeta plus polarization quality with additional diffuse s-type and p-type functions,denoted DZP++.The geometries are fully optimized with each density functional theory method.Harmonic vibrational frequencies were found to be within 3.1% of available experimental values for most functionals.Two different types of the neutral-anion energy separations reported in this work are the adiabatic electron affinity and the vertical detachment energy.The most reliable adiabatic electron affinities obtained at the DZP++BP86 level of theory are 1.150(CH3OO),1.124(C2H5OO),1.146(n-C3H7OO),1.173(n-C4H9OO),1.184(n-C5H11OO),1.145(i-C3H7OO),and 1.114 eV(r-C4H9OO).Compared with the experimental values,the average absolute error of the BPW91 method is 0.05 eV.