Tetrathiafulvalene-Oligo(para-phenyleneethynylene) Conjugates: Formation of Multiple Mixed-Valence Complexes upon Electrochemical Oxidation

0392849 - ÚOCHB 2014 RIV DE eng J - Journal Article
Lipnická, Šárka - Bělohradský, Martin - Kolivoška, Viliam - Pospíšil, Lubomír - Hromadová, Magdaléna - Pohl, Radek - Vacek Chocholoušová, Jana - Vacek, Jaroslav - Fiedler, Jan - Stará, Irena G. - Starý, Ivo
Tetrathiafulvalene-Oligo(para-phenyleneethynylene) Conjugates: Formation of Multiple Mixed-Valence Complexes upon Electrochemical Oxidation.
Chemistry - A European Journal. Roč. 19, č. 19 (2013), s. 6108-6121. ISSN 0947-6539. E-ISSN 1521-3765
R&D Projects: GA ČR GAP207/10/2214; GA ČR GA203/09/0705; GA ČR GA203/09/1802; GA MŠMT 7E09054; GA AV ČR IAA400400802
EU Projects: European Commission(XE) 213382 - FUNMOL
Institutional support: RVO:61388963 ; RVO:61388955
Keywords : cross-coupling * donor-acceptor systems * tetrathiofulvalene * oligomers * electrochemistry
Subject RIV: CC - Organic Chemistry; CF - Physical ; Theoretical Chemistry (UFCH-W)
Impact factor: 5.696, year: 2013

Short monodisperse oligo(para-phenyleneethynylene) (pOPE) units bearing laterally attached tetrathio-substituted tetrathiofulvalene (TTF) units have been synthesised from functionalised aromatic building blocks by using the Sonogashira cross-coupling methodology. The unusual redox properties of these TTF-pOPE conjugates were observed by employing electrochemical methods, such as cyclic voltammetry and exhaustive electrolysis. We found that formally one half of the TTF units in the pOPE monomer 1, dimer 2, and trimer 3 (with 2, 4, and 6 TTF units, respectively) are electrochemically silent during the first-step oxidation at 0.49 V. We propose the formation of persistent mixed-valence complexes from the TTF and TTF+center dot units present in an equal ratio. Such mixed-valence dyads (single or multiple in the partially oxidised 1-3) exhibit an unusual stability towards oxidation until the potential of the second oxidation at 0.84 V is achieved. This finding suggests that below this potential the oxidation of the respective mix-valence complexes is extremely slow.
Permanent Link: http://hdl.handle.net/11104/0221602