Radical anions and radical trianions of tetracyanoarenoquinodimethanes. An ESR and ENDOR study

Gerson, Fabian; Heckendorn, René; Cowan, Dwaine O.; Kini, Arawinda M.; Maxfield, McRae

doi:10.1021/ja00362a002

Cited by 45 publications

(11 citation statements)

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“…The EPR shows two signals centred at g=2.0079 and g= 2.0032 corresponding to the cation radical 9 +• and to the anion radical TCNQF4 -• , respectively. [34] The measured area of both signals is in accordance with the formation of a 1:1 9-TCNQF4 complex. In the UV-vis absorption spectrum (Figure 5a) it is clearly observed the shift of the S0S1 transition of the neutral TCNQ F4 at 393 nm to 405 nm corresponding to the D0D2 transition and the appearing of other local maxima at 749 and 831 nm due to the D0D1 transition of the formed specieTCNQF4 -• .…”

Section: Electrochemical Characterization and Charge Transfer Compounsupporting

confidence: 62%

Synthesis of a vinylogue tetrathiafulvalene derivative and study of its charge transfer complex with TCNQF4

et al. 2019

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Efficient syntheses of a vinylogue TTF derivative bearing four cyanoethylsulfanyl substituents, 9 is described. Cyclic voltammetry establishes that the novel compound shows good donor properties and a reduced on-site coulombic repulsion. Single crystal X-ray structure determination shows that the molecule has a planar structure of the conjugated moiety with a slipped π−π stacking organization in the crystal parallel to the crystallographic a axis. EPR, UV-Vis and IR spectroscopies show that 9 forms a charge transfer complex with TCNQF4. EPR studies allow for the recognition of the 3:2 stoichiometry ratio between donor and acceptor while IR spectroscopy gave the estimation of the ionicity of the complex, which was found to be 0.31.

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Section: Electrochemical Characterization and Charge Transfer Compounsupporting

confidence: 62%

Synthesis of a vinylogue tetrathiafulvalene derivative and study of its charge transfer complex with TCNQF4

et al. 2019

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“…The voltammograms of compounds 6 ± 8 (exemplified in Figure 6 for 6 d and 7 d) also show a reduction wave on forming the corresponding radical anion, for which the negative charge is presumably located on the acceptor group, as has been proved for TCNQ derivatives. [23] A second, poorly defined reduction wave is observed in all cases at more negative potentials, whose assignment is discussed below on the basis of ab initio calculations. The first reduction potential of the precursor ketones 6 is cathodically shifted by approximately 0.5 V compared to 7 and 8, owing to the lower acceptor ability of the ketone group.…”

Section: Compoundmentioning

confidence: 92%

Donor–π-Acceptor Species Derived from Functionalised 1,3-Dithiol-2-ylidene Anthracene Donor Units Exhibiting Photoinduced Electron Transfer Properties: Spectroscopic, Electrochemical, X-Ray Crystallographic and Theoretical Studies

Batsanov,

Bryce,

Coffin

et al. 1998

Chem. Eur. J.

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Novel single-component donor ± acceptor species 7 and 8 have been synthesised from substituted 10-(1,3-dithiol-2-ylidene)anthracen-9(10H)one 6 by reaction with Lehnerts reagent and with N,N'-bis(trimethylsilyl)carbodiimide, respectively. The steady-state UV/visible spectra of these systems contain a solvatochromic band arising from intramolecular charge transfer between the donor and acceptor groups. Ultrafast time-resolved spectroscopy shows that the excited state formed on photolysis has a lifetime of 170 ± 400 ps, which depends strongly on solvent polarity. Cyclic voltammetric data indicate the presence of two active redox centres in the molecules: electrochemical oxidation and reduction form cation radicals and anion radicals, respectively. The X-ray crystal structures of compounds 6 a, 7 b and 11 a reveal that all three molecules are severely distorted from planarity, with the central ring of the anthracenediylidene moiety adopting a boat conformation. The molecular structures of 6, 7, and 11 have been investigated theoretically at the ab initio 6 ± 31G* level. Calculated geometries are in good agreement with the X-ray data and clearly show the decrease in steric hindrance along the series 11 b 7 b 8 b 6. The calculations support the intramolecular charge-transfer nature of the lowest energy absorption band observed for 6, 7 and 8, and explain the origin of the redox properties for these compounds. The optimised geometries of the cation radical, anion radical and dianion of compound 7 illustrate the structural changes induced by the charging process. For the dianion, the steric interactions are alleviated by rotation of the acceptor dicyanomethylene unit, but the presence of the donor dithiole group hinders the achievement of a fully aromatic planar structure for the central anthracene skeleton.

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“…The ${E_{{\rm{red2}}}^{{\rm{onset}}} }$ of TCPQDI‐OC8 and TCPQDI‐OC10 were close to values of TCPQ. The onset ${E_{{\rm{red1}}}^{{\rm{onset}}} }$ and ${E_{{\rm{red2}}}^{{\rm{onset}}} }$ of TCPQDIs may correspond to the radical anion and dianion of the TCPQ unit,2 whose negative charges are mainly located at two the dicyanomethylene groups 10. The ${E_{{\rm{red1}}}^{{\rm{onset}}} }$ of compounds PQDI‐OC8 and PQDI‐OC10 (−0.60 and −0.62 eV) were much more positive than 6,13‐pentacenequinone (−1.50 eV)11 but slightly less negative than TCPQ (−0.56 eV), which may also be ascribed to the introduction of tetracarboxylic diimide that acts as an electron‐affinity unit.…”

Section: Methodsmentioning

confidence: 99%

Synthesis and Characterization of N,N′‐Substituted 15,15,16,16‐Tetracyano‐6,13‐pentacenequinodimethane‐2,3,9,10‐tetracarboxylic Diimide Derivatives

Wu¹,

Chen²,

Guo³

et al. 2012

Asian J Org Chem

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How low can you go? N,N′‐substituted 15,15,16,16‐tetracyano‐6,13‐pentacenequinodimethane‐2,3,9,10‐tetracarboxylic diimide derivatives (TCPQDI‐OC8 and TCPQDI‐OC10) were prepared in the presence of Lehnert's reagent at room temperature in good yields from the corresponding quinones. The tetracarboxylic diimide units in TCPQDI derivatives increase the π delocalization and lead to low LUMO energy levels of less than −4.0 eV.

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Radical anions and radical trianions of tetracyanoarenoquinodimethanes. An ESR and ENDOR study

Cited by 45 publications

References 0 publications

Synthesis of a vinylogue tetrathiafulvalene derivative and study of its charge transfer complex with TCNQF4

Synthesis of a vinylogue tetrathiafulvalene derivative and study of its charge transfer complex with TCNQF4

Donor–π-Acceptor Species Derived from Functionalised 1,3-Dithiol-2-ylidene Anthracene Donor Units Exhibiting Photoinduced Electron Transfer Properties: Spectroscopic, Electrochemical, X-Ray Crystallographic and Theoretical Studies

Synthesis and Characterization of N,N′‐Substituted 15,15,16,16‐Tetracyano‐6,13‐pentacenequinodimethane‐2,3,9,10‐tetracarboxylic Diimide Derivatives

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