Theoretical study of the triplet state aryl cations recombination: A possible route to unusually stable doubly charged biphenyl cations
2013 (English)In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 113, no 24, 2580-2588 p.Article in journal (Refereed) Published
The self-recombination reactions of 4-aminophenyl cations and parent phenyl cations, each in ground triplet states, are studied within the framework of density functional theory. Only the total zero spin (singlet state) is chosen, as the quintet and triplet counterparts are nonreactive in these systems. The recombination products are the benzidine and biphenyl doubly charged cations. These species are unexpectedly stable. The transition state of the 4-aminophenyl cations reaction is located at the distance of about 4.0 Å between the ipso-carbon atoms. The activation barrier is predominantly formed by electrostatic repulsion between two cations and is estimated to be 27.6 kcal mol-1 [B3LYP/6-311+G(d,p)]. Similar results are obtained for the phenyl cations recombination. The general importance of the participation of other aryl cations in analogous organic reactions is discussed. © 2013 Wiley Periodicals, Inc. The chemical reactivity of diamagnetic molecules is largely determined by the properties of their triplet excited states rather than their closed-shell ground singlet state. As an example of this type of "spin-catalysis," the self-recombination reaction of the triplet state 4-aminophenyl cations leads to the formation of the benzidine dication. The corresponding transition state is "reactant-like" and located at the Cipsoï£¿Cipso interatomic distance of 4.0 Å.
Place, publisher, year, edition, pages
2013. Vol. 113, no 24, 2580-2588 p.
aryl cation, biphenyl derivative, organic dication, self-recombination, triplet state, Aryl cations, Biphenyl derivatives, Dications, Condensed matter physics, Molecular physics, Quantum chemistry, Positive ions
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:kth:diva-139428DOI: 10.1002/qua.24509ScopusID: 2-s2.0-84961977863OAI: oai:DiVA.org:kth-139428DiVA: diva2:688538
QC 201401172014-01-172014-01-132014-01-17Bibliographically approved