The first evidence for the generation of radicals and formation of electrically conducting molecular materials by protic doping of tetrathiafulvalenes
Source abstract
Abstract
Protic acid doping of organic materials can be used to form conductive materials, see Figure. In an attempt to identify the mechanism of charge transfer in materials formed in this way, this first evidence is presented for the occurrence of radicals in the TTF + TTFH⊕ system (TTF us tetrathiafulvalene). magnified image
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Organic and Molecular Conductors Research · Conducting polymers and applications · Perovskite Materials and Applications
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (28)
Show source-provided references
1. 10.1016/0032-3861(84)90115-010.1016/0032-3861(84)90115-0 ↗
2. (b)W. S.Huang A. G.MacDiarmid A. J.Epstein J. Chem. Soc. Chem. Commun.1987 1784.10.1039/c39870001784 ↗
3. 10.1016/0379-6779(87)90572-810.1016/0379-6779(87)90572-8 ↗
4. 10.1016/0379-6779(89)90648-610.1016/0379-6779(89)90648-6 ↗
5. (e)C. W.Spangler L.Picchioti P.Bryson K. O.Havelka L. R.Dalton J. Chem. Soc. Chem. Commun.1992 145.10.1039/c39920000145 ↗
6. (f)C. W.Spangler P.Bryson P. K.Liu L. R.Dalton J. Chem. Soc. Chem. Commun.1992 253.10.1039/c39920000253 ↗
7. (g)M.Giffard J. P.Buisson J. P.Busnel C.Godon S.Lefrant T. P.Nguyen J. Chem. Res.1993 126.
8. 10.1021/ic00060a01010.1021/ic00060a010 ↗
9. 10.1039/cs993220029910.1039/cs9932200299 ↗
10. 10.3891/acta.chem.scand.45-109310.3891/acta.chem.scand.45-1093 ↗
11. 10.3891/acta.chem.scand.46-063010.3891/acta.chem.scand.46-0630 ↗
12. M.Giffard P.Frère A.Gorgues A.Riou J.Roncali L.Toupet J. Chem. Soc. Chem. Commun.1993 944.10.1039/C39930000944 ↗
13. NMR spectra were recorded at 60 MHz on a Varian EM 360 A or at 270 MHz on a Jeol GSX 270 WB spectrometer. ESR spectra were recorded on a Bruker ER 200 or on a Varian E‐112 spectrometer both operating at X‐band.
14. Carrington A. · 1967
15. McLauchlan K. A. · 1972
16. 10.1063/1.172686110.1063/1.1726861 ↗
17. (d)I.Baxter J. K. M.Sanders J. Chem. Soc. Chem. Commun.1974 255.10.1039/c39740000255 ↗
18. 10.1021/ja00481a01010.1021/ja00481a010 ↗
19. According to the electron transfer theory spin concentrations may also be estimated from NMR: in the concentration conditions of Fig. 1c the observed contact shift δc = 0.43 ppm = 115 Hz leads via the equation (see [5e]) δc =‐ahfpgeβeH/(4kT) assuming perfect conditions of fast exchange to a paramagnetic fraction fp= [TTF·⊕]/[TTF] = 4.7 × 10−3 corresponding to a spin concentration of ∼ 10−3moll−1. The hyperfine coupling constant in TTF·⊕ |aH| = 0.126 mT has been previously determined [9] from isolated TTF·⊕ Cl⊖. As a result of exchange and relaxation phenomena our own ESR spectra did not display hyperfine structure the upfield direction of our NMR contact shift δc indicates not surprisingly. thataHis negative [5].
20. Of course an acetonitrile solution of TTF does not give any ESR signal in the absence of TTFH⊕ BF.
21. Moderate time dependence of ESR intensity (30% slow decrease in 24 h after fast initial increase) was observed in the TTF + TTFH⊕solution.
22. F.Wudl O. M.Smith E. J.Hufnagel J. Chem. Soc. Chem. Commun.1970 1453.10.1039/c29700001453 ↗
23. The unsymmetrical shape of our ESR spectra (see Fig. 2) suggests the possible presence of two radical species both with a g value close to 2.008.
24. TTFH⊕ BFis obtained by protonation of TTF by ethereal tetrafluoroboric acid; it is deprotonated back to TTF by water [3]. Thus neglecting medium effects the pKaof TTFH⊕should lie roughly between the pKaof Et2OH⊕(–3.6) [12a] and 0.
25. Charlot G. · 1966
26. 1993
27. 10.1016/S0040-4020(01)88478-710.1016/S0040-4020(01)88478-7 ↗
28. Kroschwitz J. I. · 1988