%0 Journal Article %A Jia, Hong-Peng %A Ding, Jie %A Ran, Ying-Fen %A Liu, Shi-Xia %A Blum, Carmen %A Petkova, Irina %A Hauser, Andreas %A Decurtins, Silvio %T 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 %J Chemistry - An Asian Journal %@ 1861-4728 %V 6 %N 12 %P 3312-3321 %D 2011 %K charge transfer %K donor-acceptor systems %K nanographene %K redox chemistry %K tetrathiafulvalene %U http://onlinelibrary.wiley.com/doi/10.1002/asia.201100515/abstract %R 10.1002/asia.201100515 %U http://archive-ouverte.unige.ch/unige:18010 %X 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 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 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 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, leading to the formation of [1•+]2 at room temperature in solution due to the stabilizing effect arising 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 CH2Cl2.