Incisive structure-spectroscopic correlation in oligothiophenes functionalized with (±) inductive/mesomeric fluorine groups

Joint Raman and DFT study

Juan Casado, Victor Hernández, María C Ruiz Delgado, Rocío P. Ortiz, Juan T López Navarrete, Antonio Facchetti, Tobin J Marks

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

This paper presents a combined experimental Raman and density functional theory (DFT) study of a series of oligothiophenes with variable π-core lengths and substituted at the α,ω- and β,β′- terminal positions with perfluorohexyl, perfluorohexylcarbonyl, perfluoroarene, and cyano groups. The study covers the neutral and the electrochemically oxidized samples. The spectra have been assigned with the help of B3LYP/6-31G** calculations and interpreted by the predictions of effective conjugation coordinate (ECC) theory. Direct relationships between the bond length alternation (BLA) parameters and the Raman wavenumbers of the two most important bands of the spectra have been outlined showing the collective character of their electronic and vibrational properties. It is found that the topology of the thienyl electronic structure is not uniform along the conjugated core with the external rings more aromatic, whereas for the innermost part the π-electron delocalization is greater and extends with the increment of chain length. Perfluorohexyl substitution finely tunes the electronic properties via negative inductive effects. The β,β′ isomers exhibit larger conformational distortion, which strongly modifies the mean conjugation length. Oxidation provokes electronic structure quinoidization spreading over the whole system but more marked in the central part of the π-core. The Raman features associated to quinoidization in the oxidized species have been interpreted in relation to the oligomer core length and the substitution regiochemistry.

Original languageEnglish
Pages (from-to)13364-13372
Number of pages9
JournalJournal of the American Chemical Society
Volume127
Issue number38
DOIs
Publication statusPublished - Sep 28 2005

Fingerprint

Fluorine
Electronic structure
Density functional theory
Substitution reactions
Joints
Electrons
Bond length
Chain length
Oligomers
Isomers
Electronic properties
Topology
Oxidation

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Incisive structure-spectroscopic correlation in oligothiophenes functionalized with (±) inductive/mesomeric fluorine groups : Joint Raman and DFT study. / Casado, Juan; Hernández, Victor; Delgado, María C Ruiz; Ortiz, Rocío P.; Navarrete, Juan T López; Facchetti, Antonio; Marks, Tobin J.

In: Journal of the American Chemical Society, Vol. 127, No. 38, 28.09.2005, p. 13364-13372.

Research output: Contribution to journalArticle

Casado, Juan ; Hernández, Victor ; Delgado, María C Ruiz ; Ortiz, Rocío P. ; Navarrete, Juan T López ; Facchetti, Antonio ; Marks, Tobin J. / Incisive structure-spectroscopic correlation in oligothiophenes functionalized with (±) inductive/mesomeric fluorine groups : Joint Raman and DFT study. In: Journal of the American Chemical Society. 2005 ; Vol. 127, No. 38. pp. 13364-13372.
@article{2224361ce8d643b8a45bc1ab0b88bec8,
title = "Incisive structure-spectroscopic correlation in oligothiophenes functionalized with (±) inductive/mesomeric fluorine groups: Joint Raman and DFT study",
abstract = "This paper presents a combined experimental Raman and density functional theory (DFT) study of a series of oligothiophenes with variable π-core lengths and substituted at the α,ω- and β,β′- terminal positions with perfluorohexyl, perfluorohexylcarbonyl, perfluoroarene, and cyano groups. The study covers the neutral and the electrochemically oxidized samples. The spectra have been assigned with the help of B3LYP/6-31G** calculations and interpreted by the predictions of effective conjugation coordinate (ECC) theory. Direct relationships between the bond length alternation (BLA) parameters and the Raman wavenumbers of the two most important bands of the spectra have been outlined showing the collective character of their electronic and vibrational properties. It is found that the topology of the thienyl electronic structure is not uniform along the conjugated core with the external rings more aromatic, whereas for the innermost part the π-electron delocalization is greater and extends with the increment of chain length. Perfluorohexyl substitution finely tunes the electronic properties via negative inductive effects. The β,β′ isomers exhibit larger conformational distortion, which strongly modifies the mean conjugation length. Oxidation provokes electronic structure quinoidization spreading over the whole system but more marked in the central part of the π-core. The Raman features associated to quinoidization in the oxidized species have been interpreted in relation to the oligomer core length and the substitution regiochemistry.",
author = "Juan Casado and Victor Hern{\'a}ndez and Delgado, {Mar{\'i}a C Ruiz} and Ortiz, {Roc{\'i}o P.} and Navarrete, {Juan T L{\'o}pez} and Antonio Facchetti and Marks, {Tobin J}",
year = "2005",
month = "9",
day = "28",
doi = "10.1021/ja053296n",
language = "English",
volume = "127",
pages = "13364--13372",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "38",

}

TY - JOUR

T1 - Incisive structure-spectroscopic correlation in oligothiophenes functionalized with (±) inductive/mesomeric fluorine groups

T2 - Joint Raman and DFT study

AU - Casado, Juan

AU - Hernández, Victor

AU - Delgado, María C Ruiz

AU - Ortiz, Rocío P.

AU - Navarrete, Juan T López

AU - Facchetti, Antonio

AU - Marks, Tobin J

PY - 2005/9/28

Y1 - 2005/9/28

N2 - This paper presents a combined experimental Raman and density functional theory (DFT) study of a series of oligothiophenes with variable π-core lengths and substituted at the α,ω- and β,β′- terminal positions with perfluorohexyl, perfluorohexylcarbonyl, perfluoroarene, and cyano groups. The study covers the neutral and the electrochemically oxidized samples. The spectra have been assigned with the help of B3LYP/6-31G** calculations and interpreted by the predictions of effective conjugation coordinate (ECC) theory. Direct relationships between the bond length alternation (BLA) parameters and the Raman wavenumbers of the two most important bands of the spectra have been outlined showing the collective character of their electronic and vibrational properties. It is found that the topology of the thienyl electronic structure is not uniform along the conjugated core with the external rings more aromatic, whereas for the innermost part the π-electron delocalization is greater and extends with the increment of chain length. Perfluorohexyl substitution finely tunes the electronic properties via negative inductive effects. The β,β′ isomers exhibit larger conformational distortion, which strongly modifies the mean conjugation length. Oxidation provokes electronic structure quinoidization spreading over the whole system but more marked in the central part of the π-core. The Raman features associated to quinoidization in the oxidized species have been interpreted in relation to the oligomer core length and the substitution regiochemistry.

AB - This paper presents a combined experimental Raman and density functional theory (DFT) study of a series of oligothiophenes with variable π-core lengths and substituted at the α,ω- and β,β′- terminal positions with perfluorohexyl, perfluorohexylcarbonyl, perfluoroarene, and cyano groups. The study covers the neutral and the electrochemically oxidized samples. The spectra have been assigned with the help of B3LYP/6-31G** calculations and interpreted by the predictions of effective conjugation coordinate (ECC) theory. Direct relationships between the bond length alternation (BLA) parameters and the Raman wavenumbers of the two most important bands of the spectra have been outlined showing the collective character of their electronic and vibrational properties. It is found that the topology of the thienyl electronic structure is not uniform along the conjugated core with the external rings more aromatic, whereas for the innermost part the π-electron delocalization is greater and extends with the increment of chain length. Perfluorohexyl substitution finely tunes the electronic properties via negative inductive effects. The β,β′ isomers exhibit larger conformational distortion, which strongly modifies the mean conjugation length. Oxidation provokes electronic structure quinoidization spreading over the whole system but more marked in the central part of the π-core. The Raman features associated to quinoidization in the oxidized species have been interpreted in relation to the oligomer core length and the substitution regiochemistry.

UR - http://www.scopus.com/inward/record.url?scp=25444502382&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=25444502382&partnerID=8YFLogxK

U2 - 10.1021/ja053296n

DO - 10.1021/ja053296n

M3 - Article

VL - 127

SP - 13364

EP - 13372

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 38

ER -