title: Nature of bonding in the cyclization reactions of (2-Ethynylphenyl)triazene and 2-Ethynylstyrene.
abstract: The topological analysis of the electron localization function (ELF) has been applied to explore the nature of bonding in thermal cyclizations of (2-ethynylphenyl)triazene and 2-ethynylstyrene. These processes have been proposed to occur through both five- (i.e., coarctate) and six-membered (i.e., pericyclic) transition states. The analysis of electron delocalization, as measured from an irreducible ELF f-localization domain reduction diagram, allows us to characterize these cyclizations of 2-ethynylstyrene in terms of a more pronounced pericyclic or coarctate character than those associated with (2-ethynylphenyl)triazene. The latter evolve through pseudopericyclic and pseudocoarctate pathways. It is found that ELF results are also in good agreement with recent magnetic evidence data obtained from the anisotropy of induced current density (ACID) calculations.
authors.affiliation: Departamento de Ciencias Químicas, Facultad de Ecología y Recursos Naturales, Universidad Andrés Bello, Avenida República 275, Santiago, Chile.
authors.forename: C
authors.initials: C
authors.lastname: Cárdenas
authors.forename: E
authors.initials: E
authors.lastname: Chamorro
authors.forename: R
authors.initials: R
authors.lastname: Notario