charge transfer (CT) complexes

The reactions of ketotifen fumarate (KT) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π acceptors to form charge transfer (CT) complexes were evaluated in this study. Experimental and theoretical approaches, including density function theory (DFT), were used to obtain the comprehensive, reliable, and accurate structure elucidation of the developed CT complexes. The CT complexes (KT-DDQ and KT-TCNQ) were monitored at 485 and 843 nm, respectively, and the calibration curve ranged from 10 to 100 ppm for KT-DDQ and 2.5 to 40 ppm for KT-TCNQ. The spectrophotometric methods were validated for the determination of KT, and the stability of the CT complexes was assessed by studying the corresponding spectroscopic physical parameters. The molar ratio of KT:DDQ and KT:TCNQ was estimated at 1:1 using Job’s method, which was compatible with the results obtained using the Benesi–Hildebrand equation. Using these complexes, the quantitative determination of KT in its dosage form was successful.

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Charge Transfer Molecular Complexes of 4-(Dimethylamino)pyridine with Some Conventional and Unconventional Acceptors Involving Fluoroarenes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20061359 ◽

2006 ◽

Vol 71 (9) ◽

pp. 1359-1370 ◽

Cited By ~ 11

Author(s):

Usama M. Rabie

Keyword(s):

Charge Transfer ◽

Nmr Spectra ◽

Molecular Complexes ◽

Outer Sphere ◽

Formation Constants ◽

Stoichiometric Ratio ◽

Spectral Bands ◽

Elemental Analyses ◽

Ct Complexes ◽

Solid Complexes

Charge transfer (CT) complexes of 4-(dimethylamino)pyridine (DMAP) with iodine as a typical σ-type acceptor and with typical π-type acceptor, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), have been synthesized and characterized. Octafluorotoluene (OFT), octafluoronaphthalene (OFN), perfluorophenanthrene (PFP), and 2,3,5,6-tetrafluoropyridine-4-carbonitrile (TFP) were also used as acceptors for interaction with DMAP. Properties of such CT complexes were investigated by UV/VIS and IR spectra, and elemental analyses of the isolated complexes. The systems DMAP-iodine and DMAP-DDQ are characterized by formation of triiodide ions (I3-) and DDQ•- anion radicals, respectively, which is proposed to occur via initial formation of outer-sphere CT complexes. The systems (DMAP-OFT, DMAP-OFN, DMAP-PFP and DMAP-TFP) are characterized by the appearance of new UV/VIS spectral bands assigned as CT bands; they also furnished the corresponding solid complexes with the stoichiometric ratio 1:1. 1H and 19F NMR spectra were used on confirming the formation of the DMAP-PFP CT complexes. The formation constants (KCT) and molar absorption coefficients (εCT) of the latter complex were obtained.

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One-dimensionality and neutral-to-ionic transition of some mixed-stack charge-transfer complexes

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:20020437 ◽

2002 ◽

Vol 12 (9) ◽

pp. 357-360

Author(s):

M. Buron ◽

E. Collet ◽

M. H. Lemée-Cailleau ◽

H. Cailleau ◽

T. Luty ◽

...

Keyword(s):

Phase Transition ◽

Charge Transfer ◽

Charge Transfer Complexes ◽

X Ray Diffraction ◽

One Dimensional ◽

Giant Dielectric ◽

Ionic Transition ◽

The One ◽

Ct Complexes ◽

Dimerization Process

Mixed-stack charge-transfer (CT) complexes undergoing the neutral-ionic (N-I) phase transition are molecular materials formed of stacks where electron donor (D) and acceptor (A) molecules regularly alternate. In the N phase, the CT is low and molecules are situated on inversion centers, while in the I phase, the increase of CT is accompanied by a lattice distortion (dimerization process and symmetry breaking). The one-dimensional (1D) architecture triggers the chain multistability by stabilizing lattice-relaxed (LR)-CT excitations ...D° A° D° A° $(D^+A^-)(D^+A^-)(D^+A^-)$ Do A" D° A° D°... These 1D nano-scale objects are at the heart of the equilibrium N-I phase transition and govern the fascinating physical properties such as giant dielectric response or photo-induced phase transformations. In this contribution, the 1D character of these critical excitations will be demonstrated by direct observation using high resolution X-Ray diffraction.

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Charge Transfer Complexes of N-Arylcarbamates with π-Acceptors

Zeitschrift für Naturforschung A ◽

10.1515/zna-1987-0314 ◽

1987 ◽

Vol 42 (3) ◽

pp. 284-288 ◽

Cited By ~ 1

Author(s):

Aboul-fetouh E. Mourad

Keyword(s):

Charge Transfer ◽

Electron Density ◽

Nmr Spectra ◽

Charge Transfer Complexes ◽

H Nmr ◽

Ct Complexes

The charge-transfer (CT) complexes of some N-arylcarbamates as donors with a number of π-acceptors have been studied spectrophotometrically. The Lewis basicities of the N-arylcarbamates as well as the types of interactions are discussed. The 1H-NMR spectra of some CT complexes with both 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and 7,7,8,8 tetracyanoquinodimethane (TCNQ) indicate a decrease of the electron density on the donor part of the complex.

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Charge Transfer Complexes of Aromatic Nitrocompounds with Disubstituted Naphthalenes. I.Spectroscopic Investigation of the Donor Behaviour of the 2,6- and 23-Dimethylnaphthalene

Zeitschrift für Naturforschung A ◽

10.1515/zna-1984-1221 ◽

1984 ◽

Vol 39 (12) ◽

pp. 1274-1278 ◽

Cited By ~ 3

Author(s):

M. H. Abdel-Kader ◽

R. M. Issa ◽

M. M. Ayad ◽

M. S. Abdel-Mottaleb

Keyword(s):

Charge Transfer ◽

Spectral Characteristics ◽

Charge Transfer Complexes ◽

Element Analysis ◽

H Nmr ◽

Aromatic Nitrocompounds ◽

Donor Acceptor ◽

The Difference ◽

Donor Behaviour ◽

Ct Complexes

The charge transfer complexes of 2,3- (I) and 2,6-Dimethylnaphthalenes (II) as electron donors with tri- and di-nitrobenzenes as electron acceptors are prepared and investigated by element analysis, IR. 1H nmr and electronic absorption spectroscopy. The results showed that I yields CT complexes of 1:1 type only while II is capable of forming 1 : 1 and 1 : 2 (donor: acceptor) compounds. The spectral characteristics of the CT complexes are pointed out and discussed. The difference in the donor behaviour between I and II is explained in the light of PPP-MO calculations.

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Building up 1-D, 2-D, and 3-D Polyiodide Frameworks by Finely Tuning the Size of Aryls on Ar-S-TTF in the Charge-Transfer (CT) Complexes of Ar-S-TTFs and Iodine

Chinese Journal of Chemistry ◽

10.1002/cjoc.201800215 ◽

2018 ◽

Vol 36 (9) ◽

pp. 845-850 ◽

Cited By ~ 3

Author(s):

Longfei Ma ◽

Haili Peng ◽

Xiaofeng Lu ◽

Lei Liu ◽

Xiangfeng Shao

Keyword(s):

Charge Transfer ◽

Ct Complexes

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Mobile and Trapped Triplet States in Single Crystals of Charge Transfer Complexes

Zeitschrift für Naturforschung A ◽

10.1515/zna-1974-0817 ◽

1974 ◽

Vol 29 (8) ◽

pp. 1216-1228 ◽

Cited By ~ 2

Author(s):

H. Möhwald ◽

E. Sackmann

Keyword(s):

Charge Transfer ◽

Delayed Fluorescence ◽

Charge Transfer Complexes ◽

Zero Field ◽

Triplet States ◽

Zero Field Splitting ◽

Triplet Energy ◽

Molecular Arrangement ◽

Ct Complexes ◽

Triplet Excitons

Homogeneously doped crystals of charge transfer (CT-) complexes were grown by incorporating aromatic guest donors in host CT-crystals. The host crystals contained 1,2.4,5-tetracyanobenzene (TCNB) as acceptor and deuterated aromatic electron donors. By using such doped crystals CT complexes in a well defined configuration may be studied. The triplet states of the guest complexes were used as ESR spectroscopic probes in order to determine the molecular arrangement in the host lattice. The zero-field-splitting (ZFS) parameters, D and E, of the triplet energy traps were determined and the degree of electron derealization in the triplet state was calculated from these values. In some cases a very strong guest host interaction (multicomplex formation) was established. A method for the determination of CT-triplet energies is described (accuracy 200 cm-1) . The phosphorescence spectrum of the anthracene-TCNB complex was obtained from the delayed emission spectra of different anthracene doped CT-crystals. The vibronic structure is identical to that of anthracene, while the O-O-band of the complex is blue shifted by 600 cm-1. It is shown that the undoped anthracene-TCNB crystal exhibits P-type delayed fluorescence and that the triplet exciton diffusion in this crystal is nearly temperature independent. In the undoped biphenyl-TCNB crystal E-type delayed fluorescence originating from the thermal depopulation of the mobile triplet excitons is established. The remarkable differences of the two types of triplet excitons are interpreted in terms of the different polarity in the triplet states of the two CT-crystals.

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The bis(ethylenedithio)tetrathiafulvalene-based ionic charge-transfer complex with 2,3-dichloro-5,6-dicyano-p-benzoquinone

Acta Crystallographica Section C Crystal Structure Communications ◽

10.1107/s0108270113003685 ◽

2013 ◽

Vol 69 (4) ◽

pp. 400-402

Author(s):

Yuki Nakagawa ◽

Yukihiro Takahashi ◽

Jun Harada ◽

Tamotsu Inabe

Keyword(s):

Charge Transfer ◽

Charge Transfer Complex ◽

Ionic Charge ◽

One Dimensional ◽

Face To Face ◽

Ladder System ◽

Donor And Acceptor ◽

Ct Complex ◽

Centrosymmetric Dimers ◽

Ct Complexes

In the ionic charge-transfer (CT) complex composed of bis(ethylenedithio)tetrathiafulvalene (ET) and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), C10H8S8·C8Cl2N2O2, the donor and acceptor molecules both form centrosymmetric dimers associated by strong face-to-face π–π interactions. The disordered DDQ molecules form a one-dimensional π-stacked column, while the ET molecules form a two-leg ladder through additional short S...S contacts between adjacent π–π-bonded dimers. The crystal structure of ET–DDQ revealed in this study will provide a valuable example of the two-leg spin ladder system, which has rarely been reported for ET-based CT complexes.

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