Utility of 2,3-dichloro-5,6-dicyano-p-benzoquinone in assay of codeine, emetine and pilocarpine

Abdel-Hamid, M. E.

doi:10.1016/0039-9140(85)80222-8

Cited by 33 publications

(3 citation statements)

References 13 publications

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“…Examination of the literature 24,[27][28][29][30] shows that in many donoracceptor systems with DDQ as an acceptor, the formation of DDQ anion radical is often noticed which are only obtained through the formation of inner complexes from the initially formed outer complexes. Mulliken 31 pointed out that a donoracceptor pair would either form the associative outer complex or the dissociative inner complex depending on the distance of approach between the donor and acceptor and the relative magnitude of the no-bond and dative wave functions.…”

Section: Electronic Spectral Studiesmentioning

confidence: 99%

Kinetic and thermodynamic studies of charge-transfer complex formation between imipramine and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (ddq) in acetonitrile and dichloromethane solutions

Hasani

Shariati-Rad

2015

S.Afr.j.chem

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Spectro-kinetic studies revealed the formation of charge-transfer (CT) complex of imipramine as an electron donor with ð acceptor 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in acetonitrile and dichloromethane solutions. The resulted CT complexes exhibit spectra that were remarkably different from those of the donor and acceptor. The stoichiometry of the resulting complex was found to be 1:1 by the method of Job's continuous variation. The formation constants and thermodynamic parameters of the resulting electron-donor-acceptor (DA) complexes were determined by Benesi-Hildebrand and van't Hoff equations, respectively. The time-dependent spectra recorded after mixing donor and acceptor has been related to an immediate formation of DA complex, which is followed by two relatively slow consecutive reactions. The pseudo-first-order rate constants for the formation of the ionic intermediate and the final product have been evaluated at various temperatures by computer fitting of the absorbance-time data to appropriate equations. The activation parameters, i.e. activation energy, enthalpy, and entropy of activation were computed from temperature dependence of the rate constants. The observed results afford evidence concerning the critical role of solvent polarity on the kinetics and stability of the resulting charge transfer complexes. The ionization potential of the donor in the two solvents was estimated and compared with the theoretical values.

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Section: Electronic Spectral Studiesmentioning

confidence: 99%

Kinetic and thermodynamic studies of charge-transfer complex formation between imipramine and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (ddq) in acetonitrile and dichloromethane solutions

Hasani

Shariati-Rad

2015

S.Afr.j.chem

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“…The chemistry involved in the proposed DDQ-method is based on the reaction of the basic nitrogen of SMT as n-donor with the π-acceptor DDQ to form charge transfer complex which subsequently dissociates into radical anions depending on the polarity of the solvent used. In polar solvents, such as acetonitrile, complete electron transfer from the donor to the acceptor moiety takes place with the formation of intensely colored radical anions [41], according to the following equation:D…”

Section: Reaction With π-Acceptor (Ddq)mentioning

confidence: 99%

Use of Charge Transfer Complexation Reactions for the Spectrophotometric Determination of Sumatriptan in Pharmaceuticals

et al. 2012

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Studies were carried out to use the charge-transfer reactions of sumatriptan (SMT), extracted from neutralized sumatriptan succinate (STS), as n-electron donor with the π-acceptor, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and σ-acceptor, and iodine (I2). The formation of the colored complexes was utilized for the development of simple, rapid, and accurate spectrophotometric methods for the determination of SMT in pure form as well as in its tablets. The quantification of colored products was made spectrophotometrically at 585 nm for the CT complex formed between SMT and DDQ (DDQ method) and at 375 nm for the CT complex formed between SMT and I2 (I2 method). Beer’s law is obeyed over the concentration ranges of 4.0–56.0 μg mL−1 and 2.0–28.0 for DDQ and I2, respectively, with correlation coefficients () of 0.9997 and 0.9998. The analytical parameters such as apparent molar absorptivity, Sandell’s sensitivities, and limits of detection (LOD) and quantification (LOQ) are also reported for both methods. The described methods were successfully applied to the determination of SMT in tablets. No interference was observed from the common excipients present in tablets. The reaction stoichiometry in both methods was evaluated by Job’s method of continuous variations and was found to be 1 : 1 (donor : acceptor).

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“…These interactions are generally associated with the formation of intensely colored charge transfer (CT) complexes which absorb radiation in the visible region [26,27]. Substituted quinones such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and pchloranilic acid (p-CA) have been used as π-acceptors with various donors to form CT complexes and radicals, thus enabling the determination of a number of pharmaceutical substances [28][29][30][31][32][33][34][35]. This work describes the application of the above reagents (p-CA and DDQ) for the spectrophotometric assay of RTB.…”

Section: Introductionmentioning

confidence: 99%

Utility of p-Chloranilic Acid and 2,3-Dichloro-5,6-dicyano-p-benzoquinone for the Spectrophotometric Determination of Rizatriptan Benzoate

Prashanth

Basavaiah

2012

ISRN Analytical Chemistry

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Rizatriptan is a new selective 5-HT 1B/1D agonist which is used in the treatment of migraine headaches. Two simple, rapid, accurate, and economical spectrophotometric methods are described for the determination of rizatriptan benzoate (RTB) in its pure form and pharmaceutical preparations. These methods are based on the charge-transfer complexation reaction between rizatriptan benzoate as n-electron donor and p-chloranilic acid (p-CA) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as π-acceptor to form highly colored chromogens. The chromogens formed by the reaction between RTB and p-CA peaked at 530 nm (method A) and that formed by the reaction between RTB and DDQ peaked at 590 nm (method B). Under the optimum conditions Beer's law is obeyed in the concentration range of 14-245 μg mL −1 for method A and 4-70 μg mL −1 for method B. The coefficient of correlation was found to be 0.9999 for both methods. The molar absorptivity, Sandell sensitivity, limits of detection, and quantification are also reported. The stoichiometric relationship determined by Job's continuous method was found to be 1 : 1 (drug : reagent) for both methods. Both methods were applied to determination of RTB in the pharmaceutical formulations. Results of the analysis were validated statistically.

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Utility of 2,3-dichloro-5,6-dicyano-p-benzoquinone in assay of codeine, emetine and pilocarpine

Cited by 33 publications

References 13 publications

Kinetic and thermodynamic studies of charge-transfer complex formation between imipramine and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (ddq) in acetonitrile and dichloromethane solutions

Kinetic and thermodynamic studies of charge-transfer complex formation between imipramine and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (ddq) in acetonitrile and dichloromethane solutions

Use of Charge Transfer Complexation Reactions for the Spectrophotometric Determination of Sumatriptan in Pharmaceuticals

Utility of p-Chloranilic Acid and 2,3-Dichloro-5,6-dicyano-p-benzoquinone for the Spectrophotometric Determination of Rizatriptan Benzoate

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