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

Gamal A E Mostafa,Haitham Alrabiah,Najla Almasoud,Ahmed Bakheit

doi:10.3390/molecules26072039

Abstract

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.

Highlights

Charge transfer (CT) complexes have attracted significant interest in the past few decades, owing to their wide range of applications
The conceptsPreviously, underlyingthe the concepts formationunderlying of CT complexes between of CT complexes between electron donors and acceptors have been explored in detail [13,14]
The major product of Ketotifen Fumarate (KT) with TCNQ is a green radical anion, which is anion, which is characterized by a maximum absorabance of nm (Figure characterized by a maximum absorabance of 843 nm (Figure 1)

Summary

Introduction

Charge transfer (CT) complexes have attracted significant interest in the past few decades, owing to their wide range of applications. CT complexes are formed from the reaction of two molecules a donor and an acceptor within an intermolecular system [1,2]. The electron acceptors have high affinity, whereas the donors normally have a low ionization potential. The CT complex formation involves the excitation of an electron from the donor to an empty orbital of the acceptor [1,2]. The formation of a hydrogen bond between the donor and the acceptor plays an important role in the formation of CT complexes, and these bonds determine the stability [5,6]

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Conclusion