jp025602e_si_001.pdf (64.53 kB)
Structures and Enthalpies of Formation in the Gas Phase of the Most Toxic Polychlorinated Dibenzo-p-dioxins. A DFT Study
journal contribution
posted on 2002-06-20, 00:00 authored by Luis A. León, Rafael Notario, Jairo Quijano, Claudia SánchezA theoretical study on the molecular and electronic structures and the enthalpies of formation of several
polychlorinated dibenzo-p-dioxins, PCDDs, has been carried out using DFT at the B3LYP/6-31G(d) and
B3LYP/6-311+G(3df,2p)//B3LYP/6-31G(d) levels of theory. The calculated molecular structures are planar
in all of the studied PCDDs, in agreement with the available X-ray diffraction data. NBO charges, and HOMO
and LUMO energies have also been obtained and discussed. The enthalpies of formation have been calculated
through isodesmic reactions, and the
values obtained have been compared with the few available
experimental values and with values estimated by other authors using semiempirical methods or group additivity
approaches.