en
Scientific article
English

Targeting π-Conjugated Multiple Donor-Acceptor Motifs Exemplified by Tetrathiafulvalene-Linked Quinoxalines and Tetrabenz[bc,ef,hi,uv]ovalenes: Synthesis, Spectroscopic, Electrochemical, and Theoretical Characterization

Published inChemistry - an Asian journal, vol. 6, no. 12, p. 3312-3321
Publication date2011
Abstract

An efficient synthetic approach to a symmetrically functionalized tetrathiafulvalene (TTF) derivative with two diamine moieties, 2-[5,6-diamino-4,7-bis(4-pentylphenoxy)-1,3-benzodithiol-2-ylidene]-4,7-bis(4-pentylphenoxy)-1,3-benzodithiole-5,6-diamine (2), is reported. The subsequent Schiff-base reactions of 2 afford large π-conjugated multiple donor–acceptor (D–A) arrays, for example, the triad 2-[4,9-bis(4-pentylphenoxy)-1,3-dithiolo[4,5-g]quinoxalin-2-ylidene]-4,9-bis(4-pentylphenoxy)-1,3-dithiolo[4,5-g]quinoxaline (8) and the corresponding tetrabenz[bc,ef,hi,uv]ovalene-fused pentad 1, in good yields and high purity. The novel redox-active nanographene 1 is so far the largest known TTF-functionalized polycyclic aromatic hydrocarbon (PAH) with a well-resolved 1H NMR spectrum. The electrochemically highly amphoteric pentad 1 and triad 8 exhibit various electronically excited charge-transfer states in different oxidation states, thus leading to intense optical intramolecular charge-transfer (ICT) absorbances over a wide spectral range. The chemical and electrochemical oxidations of 1 result in an unprecedented TTF⋅+ radical cation dimerization, thereby leading to the formation of [1⋅+]2 at room temperature in solution due to the stabilizing effect, which arises from strong π–π interactions. Moreover, ICT fluorescence is observed with large solvent-dependent Stokes shifts and quantum efficiencies of 0.05 for 1 and 0.035 for 8 in dichloromethane.

Keywords
  • Charge transfer
  • Donor–acceptor systems
  • Nanographene
  • Redox chemistry
  • Tetrathiafulvalene
Research group
Citation (ISO format)
JIA, Hong-Peng et al. Targeting π-Conjugated Multiple Donor-Acceptor Motifs Exemplified by Tetrathiafulvalene-Linked Quinoxalines and Tetrabenz[bc,ef,hi,uv]ovalenes: Synthesis, Spectroscopic, Electrochemical, and Theoretical Characterization. In: Chemistry - an Asian journal, 2011, vol. 6, n° 12, p. 3312–3321. doi: 10.1002/asia.201100515
Main files (1)
Article (Published version)
accessLevelRestricted
Identifiers
ISSN of the journal1861-471X
610views
0downloads

Technical informations

Creation01/03/2012 3:46:00 PM
First validation01/03/2012 3:46:00 PM
Update time03/14/2023 5:06:35 PM
Status update03/14/2023 5:06:35 PM
Last indexation01/15/2024 10:53:09 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack