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.

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.

scholarly journals Encapsulation and Adsorption of Halogens into Single-Walled Carbon Nanotubes

Micro ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 140-150
Author(s):  
Navaratnarajah Kuganathan ◽  
Sashikesh Ganeshalingam
Keyword(s):  
Carbon Nanotubes ◽  
Charge Transfer ◽  
Density Functional ◽  
Diatomic Molecules ◽  
Single Walled Carbon Nanotubes ◽  
Charge Transfer Complexes ◽  
Functional Theory ◽  
Single Walled Carbon ◽  
The Stability ◽  
Walled Carbon Nanotubes

Functionalisation of single-walled carbon nanotubes (SWNTs) with atoms and molecules has the potential to prepare charge–transfer complexes for numerous applications. Here, we used density functional theory with dispersion correction (DFT + D) to examine the encapsulation and adsorption efficacy of single-walled carbon nanotubes to trap halogens. Our calculations show that encapsulation is exoergic with respect to gas-phase atoms. The stability of atoms inside SWNTs is revealed by the charge transfer between nanotubes and halogens. Encapsulation of halogens in the form of diatomic molecules is favourable with respect to both atoms and diatomic molecules as reference states. The adsorption of halogens on the outer surfaces of SWNTs is also exothermic. In all cases, the degree of encapsulation, adsorption, and charge transfer is reflected by the electronegativity of halogens.

Thermodynamic study of the complexation between Nd3+ and functionalized diacetamide ligands in solution

2016 ◽  
Vol 45 (30) ◽  
pp. 11968-11975 ◽  
Author(s):  
Phuong V. Dau ◽  
Zhicheng Zhang ◽  
Phuong D. Dau ◽  
John K. Gibson ◽  
Linfeng Rao
Keyword(s):  
Aqueous Solutions ◽  
Stability Constants ◽  
Thermodynamic Study ◽  
Amine Functionalized ◽  
The Stability ◽  
Diamide Ligands

Three amine-functionalized diamide ligands form tridentate complexes with Nd3+ in aqueous solutions. The stability constants of the complexes follow the order of the ligand basicity that can be tuned by different substitutional groups.

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