title: Experimental and theoretical study of the p- and n-doped states of alkylsulfanyl octithiophenes.
abstract: The charge-transfer and spectral properties of two octithiophenes, namely 4',4''',3'(v),3(v)'-tetra(octylsulfanyl)-2,2':5',2'':5'',2''':5''',2'(v):5'(v),2(v):5(v),2(v)':5(v)',2(v)''-octithiophene and 4,3'',4(v),4(v)''-tetrabromo-4',4''',3'(v),3(v)'-tetra[(R)-2-methylbutylsulfanyl]-2,2':5',2'':5'',2''':5''',2'(v):5'(v),2(v):5(v),2(v)':5(v)',2(v)''-octithiophene, OT1 and OT2, respectively, are characterized by cyclic voltammetry and spectroelectrochemistry under ultradry conditions. The analysis of the voltammetric results shows the formation of up to the dication for both OT1 and OT2 and up to the tetraanion (OT1) and trianion (OT2) anions. The optical properties of the OT1 (2+, 1+, neutral, 1-, 2-) species were probed by in situ UV-vis-NIR spectroelectrochemistry. The calculated standard potentials at the B3LYP/cc-pVTZ level of the theory allowed the rationalization of the experimental electrochemical results. The UV-vis-NIR spectra were successfully compared with the theoretical electronic transitions and oscillator strength data obtained by time-dependent B3LYP/6-31G* calculations. Theoretical redox potentials and optical transitions properties are calculated including "the solvent effect" within the CPCM model. The consistency obtained between experimental and theoretical results indicates the existence of the hypothesized high-spin/high-charge p- and n-doped electronic states for the OT1 and OT2 octithiophenes here studied.
authors.affiliation: Dipartimento di Chimica G. Ciamician, Università di Bologna, via Selmi 2, 40126 Bologna, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Bruno
authors.forename: Francesco
authors.initials: F
authors.lastname: Paolucci
authors.forename: Massimo
authors.initials: M
authors.lastname: Marcaccio
authors.forename: Rois
authors.initials: R
authors.lastname: Benassi
authors.forename: Claudio
authors.initials: C
authors.lastname: Fontanesi
authors.forename: Adele
authors.initials: A
authors.lastname: Mucci
authors.forename: Francesca
authors.initials: F
authors.lastname: Parenti
authors.forename: Lisa
authors.initials: L
authors.lastname: Preti
authors.forename: Luisa
authors.initials: L
authors.lastname: Schenetti
authors.forename: Davide
authors.initials: D
authors.lastname: Vanossi