An ESR Study of the Radical Cations of Tetrathiafulvalene (TTF) and Electron Donors Containing the TTF Moiety

Abstract

Hyperfine data and g factors are reported for the radical cations of tetrathiafulvalene (TTF; 1) and of its derivatives 2–13. From the intense satellite spectra of 1+–13+ not only the coupling constants of the 33S isotopes in the TTF moiety could be determined, but also, in favourable cases, those of the 13C isotopes in the central double bond. The former values range from 0.370 (8+) to 0.470 mT (4+) and the latter from 0.255 (8+) to 0.360 mT (4+) in the radical cations of bis(ethylenedithio)‐TTF (8+) and tetracyano‐TTF (4+). The radical cation of TTF (1+) exhibits intermediate values, 0.425 for the 33S and 0.285 mT for the 13C isotopes. The spin population in 1+–13+ resides, to a large extent, in the central S2C  CS2 part of the π‐system. It tends to increase (decrease) by substitution with electron‐accepting (donating) groups in the 2,3,6,7‐positions of TTF.

Cu(I) coordination complex with TTF-based radical cation ligand

“…The EPR spectra of the powdered sample of [(CET-EDTTTF)CuBr 2 ] 2 obtained from room temperature to 113 K shows a well-defined signal at g = 2.010 with a peak-to-peak linewidth of 21 G. The EPR spectra obtained from the single-crystal sample also revealed the presence of only one kind of radical species. The observed g value is comparable to the g value of 2.008 for TTF salt [12], but the shift suggests that the electronic structure of the [CET-EDTTTF] Å+ moiety is somewhat altered by the complexation or that the radical cation is somewhat different from symmetric TTF derivatives. We are currently conducting a detailed single-crystal EPR study on the complex, in order to obtain further details.…”

A New Family of Sulfur Dioxide-Containing TTF Derivatives

“…The values obtained for a H are intermediate to those of 1 and the radical cation of the corresponding symmetrical TTF derivatives. [15] As expected, the 33 S coupling constants are very similar for all compounds, indicating that the spin distribution in the p system is not substantially disturbed by the substituents on the TTF core.…”

“…TMC-TTF stands for tetracarboxymethyl-tetrathiafulvalene. [b] From reference[15]. [c] From reference [20].…”

Novel Dissymmetric Tetrathiafulvalenes as Precursors of Organic Metals: Synthesis, X-ray Crystal Structures, Electrochemical Properties and Study of Their Radical Cations

“…They were characterized by UV/Vis and electron paramagnetic resonance (EPR) spectroscopy (Table 3). In the visible range, all radical cations display new absorptions [30,31] and ref. [22] Ϫ [d] From ref.…”