title: Understanding the planar tetracoordinate carbon atom: spiropentadiene dication.
abstract: The atoms in molecule theory shows that the spiropentadiene dication has a planar tetracoordinate carbon (ptC) atom stabilized mainly through the sigma bonds and this atom has a negative charge. The bonds to the ptC atom have less covalent character than the central carbon from neutral spiropentadiene. The total positive charge is spread along the structure skeleton. The analysis of the potential energy surface shows that the dication spiropentadiene has a 2.3 kcal/mol activation barrier for ring opening.
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Química, Av. Athos da Silveira Ramos 149, Cidade Universitária-Ilha do Fundão, Rio de Janeiro, Brazil.
authors.forename: Caio L
authors.initials: CL
authors.lastname: Firme
authors.forename: Narciso B P
authors.initials: NB
authors.lastname: Barreiro
authors.forename: Pierre M
authors.initials: PM
authors.lastname: Esteves
authors.forename: Rodrigo J
authors.initials: RJ
authors.lastname: Corrêa