title: π-conjugation and charge polarization in fluorene-dibenzothiophene-S,S-dioxide co-oligomers by Raman spectroscopy and quantum chemistry.
abstract: The Raman spectra of a series of fluorine (F)∕dibenzothiophene-S,S-dioxide co-oligomers (S) of different length and alternation sequences in their backbones (FSF, FFSFF, FSFSF, and FASAF; A is the -C≡C- bridge) have been recorded and simulated theoretically. It is shown that Raman spectroscopy is useful to probe π conjugation and ground state electron polarization in these molecules, phenomena directly related with the existence of intramolecular charge-transfer processes owing to the combination of electron donor (fluorene) and acceptor (dibenzothiophene-S,S-dioxide) groups. Their geometric, electronic, and vibrational properties have been studied by density functional theory B3LYP∕6-311G(2d,p) quantum chemical calculations and compared with those for fluorene homo-oligomers. Comparative studies in solution∕solid∕melted phase led to the conclusion that the Raman wavenumbers are also sensitive to intermolecular interactions.
authors.affiliation: Departamento de Química Física, Universidad de Málaga, Málaga 29071, Spain.
authors.forename: José L
authors.initials: JL
authors.lastname: Zafra
authors.forename: Juan
authors.initials: J
authors.lastname: Casado
authors.forename: Iryna I
authors.initials: II
authors.lastname: Perepichka
authors.forename: Igor F
authors.initials: IF
authors.lastname: Perepichka
authors.forename: Martin R
authors.initials: MR
authors.lastname: Bryce
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Ramírez
authors.forename: Juan T
authors.initials: JT
authors.lastname: López Navarrete