2013-05-25 16:38:25 1266 Hong-Peng Jia, Jie Ding, Ying-Fen Ran, Shi-Xia Liu, Carmen Blum, Irina Petkova, Andreas Hauser and Silvio Decurtins Jia, Hong-Peng Ding, Jie Ran, Ying-Fen Liu, Shi-Xia Blum, Carmen Petkova, Irina Hauser, Andreas Decurtins, Silvio Chemistry - An Asian Journal Chem. - Asian J. 1861-4728 2011 6 12 3312 3321 H charge transfer;donor-acceptor systems;nanographene;redox chemistry;tetrathiafulvalene charge transfer donor-acceptor systems nanographene redox chemistry tetrathiafulvalene http://onlinelibrary.wiley.com/doi/10.1002/asia.201100515/abstract http://onlinelibrary.wiley.com/doi/10.1002/asia.201100515/pdf 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.

]]> H227I453JP1255 10.1002/asia.201100515 18010 http://www.unige.ch/sciences/chifi/publis/pics/double/ref01266.png http://www.unige.ch/sciences/chifi/publis/refs_pdf/ref01266.pdf 1222 Nathalie Dupont, Ying-Fen Ran, Hong-Peng Jia, Jakob Grilj, Jie Ding, Shi-Xia Liu and Silvio Decurtins and Andreas Hauser Dupont, Nathalie Ran, Ying-Fen Jia, Hong-Peng Grilj, Jakob Ding, Jie Liu, Shi-Xia Decurtins, Silvio Hauser, Andreas Inorganic Chemistry Inorg. Chem. 0020-1669 2011 50 8 3295 3303 H http://pubs.acs.org/doi/abs/10.1021/ic101951n http://pubs.acs.org/doi/full/10.1021/ic101951n http://pubs.acs.org/doi/pdf/10.1021/ic101951n The synthesis and the photophysical properties of the complex [Ru(TTF-dppz)₂(Aqphen)]²⁺(TTF = tetrathiafulvalene, dppz = dipyrido-[3,2-a:2′,3′-c]phenazine, Aqphen = anthraquinone fused to phenanthroline via a pyrazine bridge) are described. In this molecular triad excitation into the metal−ligand charge transfer bands results in the creation of a long-lived charge separated state with TTF acting as electron donor and anthraquinone as terminal acceptor. The lifetime of the charge-separated state is 400 ns in dichloromethane at room temperature. A mechanism for the charge separation involving an intermediate charge-separated state is proposed based on transient absorption spectroscopy.

]]> H250I500P2938 10.1021/ic101951n 15004 http://www.unige.ch/sciences/chifi/publis/pics/double/ref01222.png http://www.unige.ch/sciences/chifi/publis/refs_pdf/ref01222.pdf