Crystal Structure of Monofluoro-7,7,8,8-Tetracyano-p-Quinodimethane, TCNQF. Evidence for Strong One-Dimensional Coupling of Molecular Dipole Moments

Critical dopant concentrations govern integer and fractional charge-transfer phases in doped P3HT

“…For the modeling of the occupation of the DOS in mixed host-dopant systems, we closely followed the method introduced in [36] and also detailed in [9,11,24,37]. The molecular volume densities were taken from single-crystal structures: 4.0, 3.9, and 3.7 × 10 21 cm −3 for TCNQ [38], FTCNQ [39], F2TCNQ [40], and F4TCNQ [41], respectively, as well as 4.1 × 10 21 cm −3 for P3HT [42]. The energy distribution of the HOMO and LUMO levels of each compound were assumed to follow a Gaussian distribution [26,27,36,43] described by the position of its center and of σ, the standard deviation, equal to half the FWHM.…”

Exploration of Charge-Transfer Solids Utilizing Nucleobases: Nanoarchitectures by Hydrogen-Bonds in the Ionic Assemblies of Guanine and TCNQ Derivatives

“…In salt 1 , all a – d bond lengths except one of the d bonds (1.430 Å) are consistent with those in the fully ionized state, which is in good agreement with the characterizations by IR and UV–vis-NIR spectra. Although the variation between each of the a – d bond lengths even in F n TCNQ molecules is large, a similar tendency can be observed for the compounds where n = 2 and 1 (Table ). , The charge of a TCNQ moiety (ρ) can be estimated from the C–C bond lengths using Kistenmacher’s equation, ρ = −( r – r 0 )/( r 1 – r 0 ), where r = c /( b + d ), and r 0 and r 1 are the values calculated for neutral and fully ionized TCNQ molecules, respectively. The ρ values of 1 and 3 estimated by this method are −0.95 and −1.17, respectively, which are similar to those for (Bu 4 N + )(F 4 TCNQ •– ) and (TTF •+ )(F 2 TCNQ •– ) (ρ = −1), suggesting the fully ionized state of F n TCNQ moieties.…”

“…In Table , the C–C bond lengths of the F n TCNQ molecule ( a – d , Scheme ) of salts 1 , 3 , and 5 are compared with those of neutral and fully ionized F n TCNQ species, − although the data of fully ionized F 1 TCNQ •– has not been reported. In salt 1 , all a – d bond lengths except one of the d bonds (1.430 Å) are consistent with those in the fully ionized state, which is in good agreement with the characterizations by IR and UV–vis-NIR spectra.…”

“…Although the variation between each of the a−d bond lengths even in F n TCNQ molecules is large, a similar tendency can be observed for the compounds where n = 2 and 1 (Table 5). 32,33 The charge of a TCNQ moiety (ρ) can be estimated from the C−C bond lengths using Kistenmacher's equation, 34 Although there is no short contact between the 1D F 4 TCNQ columns along the a axis owing to the intrusion of n-butyl groups, F 4 TCNQ molecules form a thick layer (thickness of 10.7 Å) in the ab plane, and the F 4 TCNQ •− and GH + layers alternate along the c axis (Figures 7 and 8). Within a column, F 4 TCNQ molecules are dimerized, where the molecules slip along the molecular long axis for intradimer stacking (Figure 8b) and along the molecular short axis for interdimer stacking (Figure 8c).…”

Gram-Scale Synthesis of 2,5-Difluoro-7,7,8,8-tetracyanoquinodimethane (F2-TCNQ)

“…Computational studies revealed that the family of F n -TCNQ molecules all have comparable LUMO energies, electron affinities (EA), and electron reorganization energies, which makes the higher experimental electron mobility for F 2 -TCNQ an apparent anomaly . Among the members of the F n -TCNQ family, F 2 -TCNQ also has a unique stacking in a single crystal structure. − The unique face-to-face crystal stacking of F 2 -TCNQ is thought to account for its phenomenal electron mobility relative to TCNQ and F 4 -TCNQ. Finally, the properties of the F n -TCNQ family have been investigated as complexes, − co-crystals, − and adducts with various metal ions and other materials. − …”