Structural Variations and Multiple Charge Transfer Transitions between Chloranil and Carbazole Derivatives

Landman, Uzi; Ledwith, A.; Marsh, Dana G.; Williams, D. J.

doi:10.1021/ma60053a025

Cited by 36 publications

(19 citation statements)

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“…The motif for the complex optimized in Configuration I is in agreement with the X-ray crystal structure of the complex between TCNQ and 9H-carbazole, [28] where the exocyclic C-C double bond is perpendicular to the C 2 axis of the carbazole. The geometry optimized for the isolated complex is consistent with the geometry proposed by Landman et al for carbazole derivatives with para-chloranil [29] where the acceptor is aligned over one of the carbazole benzene rings. We note that, in both cases, the cyano groups in the F 4 TCNQ molecule are slightly twisted out of the ring plane.…”

Section: Doi: 101002/adma201103009supporting

confidence: 84%

Surface Modification of Indium‐Tin‐Oxide Via Self‐Assembly of a Donor‐Acceptor Complex: A Density Functional Theory Study

Winget

Brédas

2011

Advanced Materials

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The authors study at the density-functional theory level the modification of the electronic structure of the ITO surface upon self-assembly of a monolayer of t-butyl carbazole-substituted phosphonic acid molecules and subsequent p-doping. The results of the calculations point to the existence of two channels for charge transfer. These channels can enhance hole injection between ITO and a hole-transport overlayer through the chemically-modified interface.

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Section: Doi: 101002/adma201103009supporting

confidence: 84%

Surface Modification of Indium‐Tin‐Oxide Via Self‐Assembly of a Donor‐Acceptor Complex: A Density Functional Theory Study

Winget

Brédas

2011

Advanced Materials

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“…In general, like other aromatic amines, the carbazole and its ring or N‐alkylated derivatives have relatively high energies for the highest occupied molecular orbital and readily participate in the formation of electron donor–acceptor complexes with a wide range of acceptors 11–14. Because of the rather unique electronic properties, advantages for the photosensitization in the cationic polymerization were expected through the combination of the carbazole compounds and onium salts.…”

Section: Resultsmentioning

confidence: 99%

Photosensitization of carbazole derivatives in cationic polymerization with a novel sensitivity to near-UV light

Chen¹,

Yamamura²,

Igarashi³

2000

J. Polym. Sci. A Polym. Chem.

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Photosensitizers based on the carbazole structure were designed and developed for cationic polymerization. Along with triarylsulfonium and diaryliodonium salts, the carbazole derivatives showed a high photosensitization effect in the cationic photopolymerization of epoxides. The photophysical properties of the carbazole derivatives were studied in terms of electronic absorption, fluorescence, and phosphorescence spectrometry. Moreover, a unique photosensitization mechanism of the carbazole derivatives was discussed after studies of the fluorescence quenching, redox behavior, and kinetics of the photopolymerization by time‐resolved fluorescence spectrometry, cyclic voltammetry, and photo differential scanning calorimetry, respectively. The results confirmed the redox photosensitization of the carbazole derivatives in cationic polymerization. The photosensitization of the carbazole and its ring or N‐alkylated derivatives occurred predominantly in singlet excited states at the rate of the diffusion limit, whereas the carbazole derivatives with carbonyl substituents sensitized onium salts via triplet excited states on the basis of the Rehm–Weller equation in the photoinduced electron‐transfer process. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 90–100, 2000

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“…Table 1 shows the photoproducts obtained from the photodecomposition of NEC in the presence of CCl, when the photolyte was neutralized by ammonia gas after irradiation (first column) and during irradiation (second column) as well as when ethanol was used as a photochemical reaction medium (third column). Such products as carbazole (C), N-(trichlorovinyl)carbazole (2), N-(P-dich1orovinyl)- (19), and 13-di-(carboethoxy)-N-ethylcarbazole (20), which form in ethanol as a solvent, indicate also the participation of the aromatic ring of the NEC molecule in secondary reactions. Figure 1 shows an energy level diagram for NEC and carbazole based on experimental data (6,12,38,39).…”

Section: Resultsmentioning

confidence: 99%

“…(9,(13)(14)(15) and N-alkyl derivatives of carbazole (1 1,16 Carbazole and its derivatives, like other aromatic amines in panied by the heterolytic dissociation of a C-Cl bond in CCl,. the presence of strong organic electron acceptors such as tetracyanoethylene, tetracyanoquinodimethane, 2,3-dichloro-5,6-dicyano-p-benzoquinone, trinitro and tetranitrofluorenones, p-chloranil, etc., form charge transfer (CT) complexes (17)(18)(19)(20)(21)(22) with new asymmetric absorption bands in the visible region of the spectrum. The asymmetry of these new CT bands was interpreted (18,19,22) as being associated with the existence of two closely lying higher occupied molecular T-orbitals of carbazoles (12).…”

Section: Introductionmentioning

confidence: 99%

“…the presence of strong organic electron acceptors such as tetracyanoethylene, tetracyanoquinodimethane, 2,3-dichloro-5,6-dicyano-p-benzoquinone, trinitro and tetranitrofluorenones, p-chloranil, etc., form charge transfer (CT) complexes (17)(18)(19)(20)(21)(22) with new asymmetric absorption bands in the visible region of the spectrum. The asymmetry of these new CT bands was interpreted (18,19,22) as being associated with the existence of two closely lying higher occupied molecular T-orbitals of carbazoles (12). ' The possibility of distinguishing two maxima in asymmetric absorption spectra of the complexes is due to the two CT transitions from the higher occupied molecular orbitals of carbazoles to the lowest vacant orbital of the acceptors.…”

Section: Introductionmentioning

confidence: 99%

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One-electron photooxidation of N-ethylcarbazole in the presence of carbon tetrachloride. Products and mechanism of the photochemical reaction

Zelent¹,

Durocher²

1985

Can. J. Chem.

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This paper is dedicated to Professor Camille Sandorfjr on the occasion of his 65th birthdayBOGUMIL ZELENT and GILLES DUROCHER. Can. J. Chem. 63, 1654 (1985.The mechanism of the photodecomposition of N-ethylcarbazole (NEC) in the presence of carbon tetrachloride has been discussed on the basis of the photoproducts identified. The photodissociation of the N-ethyl bond and the electron transfer in the transiently formed ex-CT complex, '(NEC"..-CCI.,'-)*, have been proposed as the primary photochemical processes involved irr the singlet excited NEC molecule. The latter, treated as the main process, leads to the radical cation of NEC, chloride ion, and trichloromethyl radical in the solvent cage, [NEC"CI-CCI,]. The other reactions in the system studied are analysed following the decomposition of NEC" in the presence of C1-and CCI,, which can occur by the N-ethyl group and (or) by the aromatic ring. The formation of intermediate products such as in the solvent cage gives rise to secondary photochemical reactions in the system studied. The polarity and chemical activity of the reaction media used strongly influence the nature of the secondary photochemical transformations both in and outside the solvent cage. The formation mechanism of the photochemical reaction products in CCI, when ammonia was used, after and during irradiation, has been explained mainly by the transformations of the radical a, and cation a~. as well as by the carbazyl radical P, which is also formed in the reaction medium. On the other hand, reaction of the cation y: explains the formation of the photoproducts in the irradiated solution of NEC with CClj in ethanol. These photochemical results have been compared to the photochemical reactions involved in the carbazole-CC14 system. BOGUMIL ZELENT et GILLES DUROCHER. Can. J. Chem. 63, 1654 (1985).Le mCcanisme de la photodCcomposition du Cthyl-N-carbazole (NEC) en prksence de tktrachlorure de carbone (CCI,) est analysC suite ['identification des photoproduits obtenus. La photodissociation du lien N-Cthyl ainsi que le transfert Clectronique dans le complexe excitC de transfer de charge '(NEC''...CCI,'-)* peuvent Ctre la cause de l'acte photochimique primaire suite a I'excitation du NEC dans son Ctat premier singulet. Le phototransfert Clectronique conduit I'apparition du radical cation du NEC, a I'anion chlorure et au radical trichloromCthyl dans la cage du solvant, [NECt'CI-CCI,]. La dCcomposition du radical cation en prksence de C 1 et de CCI, s'effectue par I'attaque du groupe N-Cthyl ou par le noyau aromatique. Les produits intermkdiaires suivants: dans la cage du solvant donnent lieu a ]'ensemble des rCactions photochimiques secondaires. La polarit6 ainsi que I'activitC chimique du milieu rkactionnel influencent fortement la nature des transformations photochimiques secondaires dans la cage du solvant et en dehors de celle-ci. Le mecanisme de formation des produits photochimiques dans le CCI, lorsque I'ammoniaque est ajoutC au cours et aprks I'irradiation s'explique principalement par la transformat...

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Structural Variations and Multiple Charge Transfer Transitions between Chloranil and Carbazole Derivatives

Cited by 36 publications

References 4 publications

Surface Modification of Indium‐Tin‐Oxide Via Self‐Assembly of a Donor‐Acceptor Complex: A Density Functional Theory Study

Surface Modification of Indium‐Tin‐Oxide Via Self‐Assembly of a Donor‐Acceptor Complex: A Density Functional Theory Study

Photosensitization of carbazole derivatives in cationic polymerization with a novel sensitivity to near-UV light

One-electron photooxidation of N-ethylcarbazole in the presence of carbon tetrachloride. Products and mechanism of the photochemical reaction

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