title: ESR and calculations on electronic structure of phenalenyl and phenalenyl derivative radicals.
abstract: Calculations on electronic structure of the perinaphthenyl radical and phenalenyl derivative radicals responsible for the composition of the ESR spectrum of marine diesel under heating were performed to obtain support for the experimental ESR results. The parameters calculated were the hyperfine coupling constants (A), which were then used for comparison with the experimental data. The energy-minimized structures were obtained using the density functional theory method. In all cases, the symmetry system was taken into account in theoretical calculations. The differences between experimental and theoretical values were below 7% for nearest hydrogens in molecules, named hyperfine coupling constant A (first neighbors) and 18% for farthest hydrogens atoms named hyperfine coupling constants A' (second neighbors), for all structures analyzed.
authors.affiliation: Laboratory of Fluorescence and Electron Paramagnetic Resonance (LAFLURPE)-CCE, State University of Londrina (UEL), 86057-970, Londrina, PR, Brazil.
authors.forename: Marilene Turini
authors.initials: MT
authors.lastname: Piccinato
authors.forename: Marcello Ferreira
authors.initials: MF
authors.lastname: da Costa
authors.forename: André Tsutomu
authors.initials: AT
authors.lastname: Ota
authors.forename: Carmen Luísa Barbosa
authors.initials: CL
authors.lastname: Guedes
authors.forename: Eduardo
authors.initials: E
authors.lastname: Di Mauro
keywords: DFT; ESR; crude oil; diesel; free radical; hyperfine interaction