Determination of the Stability Constants of Some Pyridines-Bromine Charge Transfer Complexes by Raman Spectroscopy

1978 ◽  
Vol 11 (4) ◽  
pp. 251-258 ◽  
Author(s):  
G. Maes ◽  
Th. Zeegers-Huyskens
Keyword(s):  
Raman Spectroscopy ◽  
Charge Transfer ◽  
Stability Constants ◽  
Charge Transfer Complexes ◽  
The Stability

scholarly journals Charge Transfer Complexes of Ketotifen with 2,3-Dichloro-5,6-dicyano-p-benzoquinone and 7,7,8,8-Tetracyanoquodimethane: Spectroscopic Characterization Studies

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2039
Author(s):  
Gamal A. E. Mostafa ◽  
Ahmed Bakheit ◽  
Najla AlMasoud ◽  
Haitham AlRabiah
Keyword(s):  
Charge Transfer ◽  
Spectroscopic Characterization ◽  
Molar Ratio ◽  
Charge Transfer Complexes ◽  
Physical Parameters ◽  
Spectrophotometric Methods ◽  
Theoretical Approaches ◽  
The Stability ◽  
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.

A Thermodynamic Study of the Charge Transfer Complexes of Iodine with Different tert-Butylcalix[4]crowns

2005 ◽  
Vol 60 (11) ◽  
pp. 1133-1137 ◽  
Author(s):  
Shehadeh A. Mizyed ◽  
Muhammad Ashram ◽  
Riyadh Saymeh ◽  
Deeb Marji
Keyword(s):  
Charge Transfer ◽  
Stability Constants ◽  
Thermodynamic Data ◽  
Chloroform Solution ◽  
Thermodynamic Study ◽  
Charge Transfer Complexes ◽  
The Stability

Formation of the charge-transfer complexes between calix[4]crowns (1 - 4) and iodine in chloroform solution was studied using UV-vis spectrophotometry. The stability constants and the thermodynamic data of the resulting 1 : 1 complexes were determined and was found to decrease with increasing the size of the crown moiety of the calixcrown. All complexes formed were found to be enthalpy stabilized, and all except the complex of 2 were entropy destabilized.

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