title: Stacking of oligo- and polythiophene cations in solution: surface tension and dielectric saturation.
abstract: The stacking of positively charged (or doped) terthiophene oligomers and quaterthiophene polymers in solution is investigated applying a recently developed unified electrostatic and cavitation model for first-principles calculations in a continuum solvent. The thermodynamic and structural patterns of the dimerization are explored in different solvents, and the distinctive roles of polarity and surface tension are characterized and analyzed. Interestingly, we discover a saturation in the stabilization effect of the dielectric screening that takes place at rather small values of epsilon(0). Moreover, we address the interactions in trimers of terthiophene cations, with the aim of generalizing the results obtained for the dimers to the case of higher-order stacks and nanoaggregates.
authors.affiliation: Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, Buenos Aires C1428EHA, Argentina. damian@qi.fcen.uba.ar
authors.forename: Damián A
authors.initials: DA
authors.lastname: Scherlis
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Fattebert
authors.forename: Nicola
authors.initials: N
authors.lastname: Marzari