Low Temperature Raman Spectra of TTF-TCNQ and other Organic Conductors

Colloidal Solutions of Organic Conductive Nanoparticles

“…21 Moreover, the frequencies of the CC Raman modes, ν 4 in TCNQ and ν 3 in TTF, are known to vary linearly as a function of the charge of these molecules. 24,25 Raman spectroscopy (Figure 3) confirms the formation of TTF−TCNQ with a charge transfer of 0.58, in agreement with that of single crystals, i.e., 0.59. The nanoparticle powder has the same structure as TTF− TCNQ monocrystal as evidenced by X-ray powder diffraction (Figure 4).…”

Self‐Assembled Architectures with Segregated Donor and Acceptor Units of a Dyad Based on a Monopyrrolo‐Annulated TTF–PTM Radical

“…[47] In the case of TTF,t he charge-sensitive vibrations are associated with C=Cs tretching, notably the Raman-active n 3 mode, which appears at 1516 in neutral TTF anda t1 420 cm À1 in the radicalc ations, and the IR-active n 14 mode, found at 1530 and 1478 cm À1 . [48][49][50] The Ramana nd IR polarized spectra of 2 ( Figure S17 in the Supporting Information) lead us to conclude that the MPTTF C=Cs tretching overlaps at around 1518 cm À1 ,w ith the abovementioned C=Cs tretching mode associated with PTM. In this complex situation, it is difficult to obtain ap recise estimate of the ionicity,b ut, nevertheless, it can be concluded that in the solid state the TTF/MPTTF subunits of both 1 and 2 dyads are in an essentially neutral state.…”

“…Moreover, it is well known that vibrational spectroscopy can provide a reliable estimate of the formal charge or degree of CT on the molecular sites 47. In the case of TTF, the charge‐sensitive vibrations are associated with CC stretching, notably the Raman‐active ν 3 mode, which appears at 1516 in neutral TTF and at 1420 cm −1 in the radical cations, and the IR‐active ν 14 mode, found at 1530 and 1478 cm −1 48–50. The Raman and IR polarized spectra of 2 (Figure S17 in the Supporting Information) lead us to conclude that the MPTTF CC stretching overlaps at around 1518 cm −1 , with the abovementioned CC stretching mode associated with PTM.…”

Nanowires of molecule-based charge-transfer salts

“…The first line, exhibiting two maxima at 1413 and 1418 cm À1 , corresponds to the n 4 a g mode in TCNQ. Using the linear relation of the TCNQ n 4 frequency vs. r (amount of charge transfer) established by Matsuzaki et al, 19 we determine a degree of charge transfer ranging from 0.65 to 0.60, in good agreement with the value of 0.59 for single crystals. The second line (1512 cm À1 ) is due to the n 2 a g mode in TTF.…”