title: Electronic interactions in a new pi-extended tetrathiafulvalene dimer.
abstract: The first pi-extended tetrathiafulvalene (exTTF) dimer in which the two exTTF units are covalently connected by 1,3-dithiole rings has been obtained in a multistep synthetic procedure involving the Ullmann cross-coupling reaction by using copper(I) thiophene-2-carboxylate (CuTC). The electronic spectrum reveals a significant electronic interaction between the exTTF units. The electrochemical study carried out by cyclic voltammetry in solution and in thin-layer conditions, and the electrochemical simulation and spectroelectrochemical (SEC) measurements confirm the electronic communication and show that the oxidation of dimer 14 occurs as two consecutive 2 e(-) processes D(0)-D(0)-->D(2+)-D(0)-->D(2+)-D(2+). Theoretical calculations, performed at the B3P86/6-31G* level, confirm the experimental findings and predict that 14(2+) exists as a delocalized D(.+)-D(.+) species in the gas phase and as a localized D(2+)-D(0) species in solution (CH(3)CN or CH(2)Cl(2)). Oxidation of 14(2+) forms the tetracation 14(4+) which is constituted by two aromatic anthracene units bearing four aromatic, almost orthogonal 1,3-dithiolium cations.
authors.affiliation: Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain.
authors.forename: Marta C
authors.initials: MC
authors.lastname: Díaz
authors.forename: Beatriz M
authors.initials: BM
authors.lastname: Illescas
authors.forename: Nazario
authors.initials: N
authors.lastname: Martín
authors.forename: Igor F
authors.initials: IF
authors.lastname: Perepichka
authors.forename: Martin R
authors.initials: MR
authors.lastname: Bryce
authors.forename: Eric
authors.initials: E
authors.lastname: Levillain
authors.forename: Rafael
authors.initials: R
authors.lastname: Viruela
authors.forename: Enrique
authors.initials: E
authors.lastname: Ortí
mesh_terms: D000873:Anthracenes / Q000737:chemistry; D019281:Dimerization; D004563:Electrochemistry; D004581:Electronics; D006571:Heterocyclic Compounds / Q000737:chemistry*; D008956:Models, Chemical; D010084:Oxidation-Reduction; D013237:Stereoisomerism
chemical_list: D000873:Anthracenes; D006571:Heterocyclic Compounds; C034020:anthracene; C063887:tetrathiafulvalene