RESUMO
In this work we define a shape entropy by calculating the Shannon's entropy of the shape function. This shape entropy and its linear response to the change in the total number of electrons of the molecule are explored as descriptors of bonding properties. Calculations on selected molecular systems were performed. According to these, shape entropy properly describes electron delocalization while its linear response to ionization predicts changes in bonding patterns. The derivative of the shape entropy proposed turned out to be fully determined by the shape function and the Fukui function.
RESUMO
The molecular and electronic structures of a series of 2-[(R-phenyl)amine]-1,4-naphthalenediones (R = m-Me, p-Me, m-Et, p-CF3, p-Hex, p-Et, m-F, m-Cl, p-OMe, p-COMe, p-Bu, m-COOH, p-Cl, p-COOH, p-Br, m-NO2, m-CN, and p-NO2) and their anions are investigated in the framework of density functional theory. The calculations are of all-electron type using a double zeta valence polarization basis set optimized for density functional theory methods. The theoretical study shows that all compounds are nonplanar. The nonplanarity can be rationalized in terms of occupied π orbitals. A linear correlation between the measured half-wave potentials and the calculated gas-phase electron affinities is found. It holds for local as well as generalized gradient corrected functionals. Structural parameters, harmonic vibrational frequencies, and adiabatic and vertical electron affinities as well as orbital and spin density plots of the studied compounds are presented.