Charge-transfer interaction of bithienyls and some thiophene derivatives with electron acceptors

1976 ◽  
Vol 54 (23) ◽  
pp. 3705-3712 ◽  
Author(s):  
Rafie Abu-Eittah ◽  
Fakhreia Al-Sugeir
Keyword(s):  
Charge Transfer ◽  
Complex Formation ◽  
Molecular Complexes ◽  
Formation Constants ◽  
Electron Acceptors ◽  
Charge Transfer Complexes ◽  
Extinction Coefficients ◽  
Charge Transfer Transitions ◽  
Different Temperatures ◽  
Thiophene Derivatives

The charge transfer complexes of 2,2′-bithienyl, 5,5′-dimethyl-2,2′-bithienyl, and some thiophene derivatives as donors with tetracyanoethylene as an acceptor have been studied spectrophotometrically. In addition, complexes of the first donor with chloranil and iodine have been studied. The formation constants and extinction coefficients of the molecular complexes formed have been determined by graphical as well as iterative methods. From measurements at different temperatures, the thermodynamic functions of the complex formation have been calculated. The ionization potentials of the donors have been obtained from the energies of the charge transfer transitions.

scholarly journals Investigation of Charge Transfer Complexes Formed between Mirtazapine and Someπ-Acceptors

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Hulya Demirhan ◽  
Mustafa Arslan ◽  
Mustafa Zengin ◽  
Mustafa Kucukislamoglu
Keyword(s):  
Charge Transfer ◽  
Dosage Form ◽  
Room Temperature ◽  
Equilibrium Constants ◽  
Formation Constants ◽  
Electron Acceptors ◽  
Spectral Studies ◽  
Charge Transfer Complexes ◽  
Ir And Nmr Spectroscopy ◽  
Ft Ir

Charge transfer complexes (CTC) of mirtazapine with tetracyanoethylene (TCNE), 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), and tetracyanoquinodimethane (TCNQ) have been studied spectrophotometrically in dichloromethane at room temperature. The stoichiometries of the complexes were found to be 1 : 1 ratio by the Job Method between mirtazapine and the acceptors. The equilibrium constants and thermodynamic parameters of the complexes were determined by the Benesi-Hildebrand and Van't Hoff equations. Mirtazapine in pure and dosage form was applied in this study. The results indicate that the formation constants for the complexes depend on the nature of electron acceptors and donor. And also the spectral studies of the complexes were determined by FT-IR and NMR spectroscopy.

CHARGE-TRANSFER COMPLEXES OF BIPHENYLENE

1966 ◽  
Vol 44 (1) ◽  
pp. 9-12 ◽  
Author(s):  
P. H. Emslie ◽  
R. Foster ◽  
R. Pickles
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Complex ◽  
Equilibrium Constants ◽  
Charge Transfer Complexes ◽  
Kcal Mole ◽  
Dichloromethane Solution ◽  
Entropy Of Formation ◽  
Charge Transfer Transitions ◽  
Different Temperatures ◽  
Enthalpy And Entropy

An attempt has been made to redetermine the enthalpy and entropy of formation of the charge-transfer complex between tetracyanoethylene and biphenylene in dichloromethane solution from measurements of the equilibrium constant at different temperatures. The results obtained under conditions where biphenylene is in excess differ from those previously published in which tetracyanoethylene was in excess. It is argued that the optimum condition for determining equilibrium constants of a 1:1 complex is when the reactants are mixed in solution in this ratio. Determinations under this condition yield ΔH = −2.6 kcal mole−1 and ΔS = −4.1 e.u.The energies of the intermolecular charge-transfer transitions of biphenylene with several different acceptors suggest that the ionization potential of biphenylene is ~7.4 eV.

Charge-Transfer Complexes of Brominated Polycyclic Aromatic Hydrocarbons

1962 ◽  
Vol 15 (2) ◽  
pp. 278 ◽  
Author(s):  
TM Spotswood
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Charge Transfer ◽  
Aromatic Hydrocarbons ◽  
Charge Transfer Complex ◽  
Equilibrium Constants ◽  
Molecular Complexes ◽  
Charge Transfer Complexes ◽  
Extinction Coefficients ◽  
Polycyclic Aromatic ◽  
Molar Extinction Coefficients

Charge-transfer complex formation between the donors 1-bromonaphthalene. 9-bromophenanthrene, 9-bromoanthracene, 3-bromopyrene, and 7-bromobenz[a]-anthracene and the acceptors iodine, tetrachlorophthalic anhydride, 1,3,5-trinitrobenzene, and 2,4,7-trinitrofluorenone has been investigated. The positions of the charge-transfer absorption maxima, apparent molar extinction coefficients, and equilibrium constants have been determined in carbon tetrachloride solution and the results compared with those for the corresponding unsubstituted polycyclic aromatic hydrocarbons. The positions of the absorption maxima of the charge-transfer bands of the brominated hydrocarbons were anomalous but the apparent molar extinction coefficients and equilibrium constants were similar to those obtained for the parent hydrocarbons. The strength of charge-transfer bonding in molecular complexes of brominated polycyclic aromatic hydrocarbons is shown to be of the same order as that in molecular complexes of the unsubstituted hydrocarbons.

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

2006 ◽  
Vol 71 (9) ◽  
pp. 1359-1370 ◽  
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.

Molecular Complexes of Cyclophanes, Part XVII Charge-Transfer Complexes of [2.2]- and [2.2.2]Paracyclophane-carbamates with π-Acceptors

1987 ◽  
Vol 42 (9) ◽  
pp. 1147-1152 ◽  
Author(s):  
Aboul-fetouh E. Mourad ◽  
Verena Lehne
Keyword(s):  
Charge Transfer ◽  
Functional Group ◽  
Lone Pair ◽  
Molecular Complexes ◽  
Charge Transfer Complexes ◽  
Electronic Interactions ◽  
H Nmr ◽  
Ct Complex ◽  
Nitrogen Lone Pair ◽  
Lone Pair Electrons

Charge-transfer (CT) complexation between some [2.2]- and [2.2.2]paracyclophane-carbamates as donors with 2,3-dichloro-5.6-dicyanobenzoquinone (DDO ) as well as tetracyanoethylene (TCNE) as π-acceptors has been evidenced by VIS. 1H NMR and IR spectroscopy. The site of interaction in the two different donor systems was determined. The results reveal no contribution of the nitrogen lone pair electrons of the carbamate functional group in the CT complexation. and the interaction is mainly of π-π* type. In addition, the existence of the transannular electronic interactions in [2.2]paracyclophane derivatives is responsible for CT complex formation.

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