Interaction of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone with aza-18-crown-6 and aza-12-crown-4. Kinetic and spectrophotometric studies in chloroform and acetonitrile solutions

Hasani, Masoumeh; Shamsipur, Mojtaba

doi:10.1039/a705366e

Cited by 20 publications

(9 citation statements)

References 33 publications

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“…The substitution of some oxygen atoms of the crown ethers by -NH-, and -S-groups has found to alter their complexing ability towards different metal ions [4]. During the past two decades, a growing interest has been focused on the complexing ability of these macrocyclic ligands as electronpair molecules towards neutral and electron accepting molecules [5][6][7][8][9][10][11][12][13][14][15][16] and, especially, molecular iodine [17][18][19][20][21][22][23][24][25][26][27][28]. Interest in such molecular complexes is largely due to their possible applications in areas like organic semiconduction, separation processes, catalysis of chemical reactions, biomimetic receptors and conversion of chemical reactions into electronic or optical signals [5,[29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic studies of charge-transfer complexation of iodine with a new benzo-substituted macrocyclic diamide in chloroform, dichloromethane and their 1:1 mixture

Alizadeh

Zanjanchi

Sharghi

et al. 2008

JICS

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Charge-transfer complexation of iodine with a new benzo-substituted macrocyclic diamide 5, 6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioxatriazacyclopentadecine-3,11(4H,12H)-dione (L) with iodine was studied spectrophotometrically in chloroform, dichloromethane and their 1:The observed time dependence of the charge-transfer band and subsequent formation of I 3 -ion are related to the slow formation of the initially formed 1:1 L.I 2 outer complex to an inner electron donor-acceptor (EDA) complex, followed by fast reaction of the inner complex with iodine to form a triiodide ion, as follows: L + I 2 o L.I 2 (outer complex), fast L.I 2 (outer complex) o (L.I + )I -(inner complex), slow (L.I + )I -(inner complex) + I 2 o (L.I + )I 3 -, fastThe pseudo-first-order rate constants for the transformation process were evaluated in different solvent systems. The stability constants of the resulting EDAr complexes were also evaluated and the solvent effect on their stability is discussed. The resulting complexes were isolated and characterized by FTIR and 1 H NMR spectroscopy.

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Section: Introductionmentioning

confidence: 99%

Spectroscopic studies of charge-transfer complexation of iodine with a new benzo-substituted macrocyclic diamide in chloroform, dichloromethane and their 1:1 mixture

Alizadeh

Zanjanchi

Sharghi

et al. 2008

JICS

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“…Furthermore, the observed gradual decrease in the intensity of the bands in the 500-600-nm spectral regions, with lapse of time, could be due to the consumption of the ionic intermediate through an irreversible chemical reaction. While the continuous increase of the 433-nm band with lapse of time is indicative of the formation of the final reaction product [44]. Such a conversion of the dative intermediate to product is indicated by a clear isosbestic point at 495 nm.…”

Section: Interaction Of Pantoprazole With Ddqmentioning

confidence: 97%

Spectroscopic studies on the dynamics of charge‐transfer interaction of pantoprazole drug with DDQ and iodine

Pandeeswaran

El‐Mossalamy

Elango

2009

Int J of Chemical Kinetics

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Spectrophotometric method was used to study the kinetics of charge-transfer (CT) complexes of pantoprazole with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and iodine. The reactions of DDQ and iodine with pantoprazole have been investigated in different solvents at three different temperatures. The products of the interactions have been isolated and characterized using UV-vis, GC-MS, FT-IR, and far-IR spectral techniques. The rate of formation of the product has been measured and discussed as a function of solvents and temperature. The iodine complex indicates the formation of the tri-iodide CT complex with a general formula [(PTZ)I] + I − 3 . The characteristic strong absorptions of I − 3 are observed around 360 and 290 nm in the electronic spectra, and the far-IR spectrum exhibits three characteristic vibrations of I − 3 unit at 156, 112, and 69 cm −1 assigned to ν as (I-I), ν s (I-I), and δ(I − 3 ), respectively. The activation parameters ( G # , S # , and H # ) were obtained from the temperature dependence of the rate constants. The influence of relative permittivity of the medium on the rate indicated that the intermediate is more polar than the reactants, and this observation was further well supported by spectral studies. Based on the spectrokinetic results, plausible mechanisms for the interaction of the drug with the chosen acceptors, which proceed via the formation of CT complexes and its transformation into final products, have been proposed.

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“…The continuous increase in absorbance at 475 nm at 60°C is indicative of formation of the final reaction product, because at this wavelength neither the acceptor nor the donor absorbs. Hence, the reaction probably appears to proceed through the initial formation of the n-π charge transfer complex, which might be transformed into the final products [14][15][16] . The proposed mechanism may be shown as follows:…”

Section: Reaction Mechanismmentioning

confidence: 99%

The Use of 2,3-dichloro-1,4-naphthaquinone for the Spectrophotometric Determination of Some Primary Aliphatic Amines in Aqueous Solution

Al-Ghabsha¹,

Al-Sabha²,

Al-Neaimy³

2009

J.Edu.Sci.

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1 . ‫يقة‬ ‫الطر‬ ‫تطبيق‬ ‫تم‬ ‫لقد‬ ‫الصيدالني‬ ‫ه‬ ‫مستحضر‬ ‫في‬ ‫أمين‬ ‫ايثانول‬ ‫تقدير‬ ‫في‬ ‫بنجاح‬ . AbstractA simple and accurate spectrophotometric method was developed for the quantitative determination of some primary aliphatic amines in aqueous solution, i.e. ethanolamine, n-butylamine and n-hexylamine. The method is based on the interaction of these amines in aqueous medium with 2,3-dichloro-1,4-naphthaquinone (DClNQ) reagent in the presence of bicarbonate buffer solution to form an orange coloured products measurable at maximum wavelength of 475 nm. Beer's law is obeyed over the concentration range of 1-30, 5-20 and 3-30g/ml for The Use of 2,3-dichloro-1,4-naphthaquinone for the Spectrophotometric … 44 ethanolamine, n-butylamine and n-hexylamine respectively. The DClNQ products were formed in the ratio of 1:1 amine: DClNQ, and their stability constants were ranged between 1.9210 5 and 4.1410 5 L.mol -1 . The method was successfully applied for the determination of ethanolamine in its pharmaceutical preparation.

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Interaction of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone with aza-18-crown-6 and aza-12-crown-4. Kinetic and spectrophotometric studies in chloroform and acetonitrile solutions

Cited by 20 publications

References 33 publications

Spectroscopic studies of charge-transfer complexation of iodine with a new benzo-substituted macrocyclic diamide in chloroform, dichloromethane and their 1:1 mixture

Spectroscopic studies of charge-transfer complexation of iodine with a new benzo-substituted macrocyclic diamide in chloroform, dichloromethane and their 1:1 mixture

Spectroscopic studies on the dynamics of charge‐transfer interaction of pantoprazole drug with DDQ and iodine

The Use of 2,3-dichloro-1,4-naphthaquinone for the Spectrophotometric Determination of Some Primary Aliphatic Amines in Aqueous Solution

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