Tetrathiafulvalene Hetero Radical Cation Dimerization in a Redox-Active [2]Catenane

Cited 33 time in webofscience Cited 0 time in scopus
  • Hit : 391
  • Download : 0
The electronic properties of tetrathiafulvalene (TTF) can be tuned by attaching electron-donating or electron-withdrawing substituents. An electron-rich macrocyclic polyether containing two TTF units of different constitutions, namely 4,4'-bis(hydroxymethyl)-tetrathiafulvalene (OTTFO) and 4,4'-bisthiotetrathiafulvalene (STTFS), has been synthesized. On two-electron oxidation, a hetero radical dimer is formed between OTTFO center dot+ and STTFS center dot+. The redox behavior of the macrocyclic polyether has been investigated by electrochemical techniques and UV-vis and electron paramagnetic resonance (EPR) spectroscopies. The [2]catenane in which the macrocyclic polyether is mechanically interlocked with the cyclobis(paraquat-p-phenylene) (CBPQT(4+)) ring has also been prepared using template-directed protocols. In the case of the [2]catenane, the formation of the TTF hetero radical dimer is prevented sterically by the CBPQT(4+) ring. After a one-electron oxidation, a 70:30 ratio of OTTFO center dot+ to STTFS center dot+ is present at equilibrium, and, as a result, two translational isomers of the [2]catenane associated with these electronically different isomeric states transpire. EPR titration spectroscopy and simulations reveal that the radical states of the two constitutionally different TTF units in the [2]catenane still experience long-range electronic intramolecular coupling interactions, despite the presence of the CBPQT(4+) ring, when one or both of them are oxidized to the radical cationic state. These findings in the case of both the free macrocyclic polyether and the [2]catenane have led to a deeper fundamental understanding of the mechanism of radical cation dimer formation between constitutionally different TTF units.
Publisher
AMER CHEMICAL SOC
Issue Date
2012-11
Language
English
Article Type
Article
Keywords

MESOPOROUS SILICA NANOPARTICLES; FIELD EFFECT TRANSISTORS; LIGHT-EMITTING-DIODES; MIXED-VALENCE; BUILDING-BLOCKS; SUPRAMOLECULAR CHEMISTRY; CONDUCTING POLYMERS; CONJUGATED POLYMERS; ROOM-TEMPERATURE; PI-DIMERS

Citation

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, v.134, no.46, pp.19136 - 19145

ISSN
0002-7863
DOI
10.1021/ja307577t
URI
http://hdl.handle.net/10203/103517
Appears in Collection
Files in This Item
There are no files associated with this item.
This item is cited by other documents in WoS
⊙ Detail Information in WoSⓡ Click to see webofscience_button
⊙ Cited 33 items in WoS Click to see citing articles in records_button

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0