Temperature, medium and structural effects on the acid dissociation constants of certain Schiff bases derived from isatin with some amino acids and aroylhydrazines

Hassaan, Aly M. A.; Quenawy, M. T. A.

doi:10.1007/bf02974479

Cited by 2 publications

(4 citation statements)

References 11 publications

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“…Since the tautomeric equilibrium studies have indicated the favorability of the keto form for the 2-indolinone derivative, we can predict that the p K a value for the protonation of the studied compounds should be close to the protonation acidity constants of 2-indolinone. The p K a value of α-protonation for indole has been reported as p K a = −3.5 which is close enough to p K a values of α-protonation for 1-methyl indole, indicating a similar protonation mechanism for these two molecules . The p K a values of studied molecules 1 to 5 , however, have p K a values ranging from 4 to 7, suggesting a different protonation pathway from indole and 1-methyl indole.…”

Section: Resultsmentioning

confidence: 56%

“…Furthermore, it seems that the mezomeric electron-donating effect of the methoxy group (CH 3 O), which is located at position 5 of the studied molecules, is reflected in molecules 1 to 4 by making them more basic compared to molecule 5 , which has no substituent at the benzenoid moiety of indole. Since the deprotonation p K a value for indole was reported as 16.97, we can conclude that the deprotonation for all studied molecules occurs at the group probably with the mechanism in Figure .…”

Section: Resultsmentioning

confidence: 65%

“…The pK a value of R-protonation for indole has been reported as pK a ) -3.5 which is close enough to pK a values of R-protonation for 1-methyl indole, indicating a similar protonation mechanism for these two molecules. 22 The pK a values of studied molecules 1 to 5, however, have pK a values ranging from 4 to 7, suggesting a different protonation pathway from indole and 1-methyl indole. So we can suggest an oxo (carbonyl) protonation for the studied molecules 1 to 5 as depicted in Scheme 2.…”

Section: Resultsmentioning

confidence: 86%

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Acid Dissociation Constants of Some Novel Isatin Thiosemicarbazone Derivatives

et al. 2010

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Section: Resultsmentioning

confidence: 56%

Section: Resultsmentioning

confidence: 65%

Section: Resultsmentioning

confidence: 86%

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Acid Dissociation Constants of Some Novel Isatin Thiosemicarbazone Derivatives

et al. 2010

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“…Bands at 3239, 3191, and 3141 cm −1 in the IR spectrum of the ligand PTHAC, Fig. 2 A, are attributed to the υ (NH) 1 [ 42 ], υ (NH) 2 [ 43 ], and υ (NH) 4 vibrations, respectively [ 44 ]. At 1704 cm −1 , there is a strong band and a shoulder and this is assigned to (C = O) [ 40 , 45 ].…”

Section: Resultsmentioning

confidence: 99%

Design, spectral, molecular modeling, antimitotic, analytical and mechanism studies of phenyl isothiocyanate Girard's T derived metal complexes

Akl,

El Mahdy,

Elbadrawy

et al. 2023

BMC Chemistry

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The ligand N-{[(phenyl amino) thioxomethyl] hydrazino carbonyl methyl} trimethyl ammonium chloride (PTHAC) was prepared by the refluxing phenyl isothiocyanate and Girard-T (trimethyl ammonium-acethydrazide) in a molar ratio (1:1). The metal complexes derived from NiCl2.6H2O, CuCl2.2H2O and Co(CH3COO)2.6H2O were synthesized and purified. The PTHAC and its Cu(II), Co(II), and Ni(II) metal complexes(1–3) were characterized using a variety of various instrumental performances such as elemental analysis, magnetic moment, spectra (IR, UV–Vis, 1H NMR, mass) and thermal analysis (TGA and DTG).The results of element analysis, magnetic moment, spectra (IR, UV–Vis, 1H NMR, mass), and thermal (TGA and DTA) analyses provide the structures of the produced ligand and its (1–3) complexes. According to the spectroscopic results, PTHAC acts as an O, N and S tridentate donor, creating a mononuclear complex with copper(II), cobalt(II), and nickel(II) ions with an octahedral geometry. All of the atomic properties, including bond lengths, bond angles, HOMO, LUMO, dipole moments, and charges, have been determined. The cytotoxic activities of the PTHAC and the produced (1–3) complexes against breast carcinoma cells have been studied and correlated to the molecular modeling. When compared to the free ligand, CoII-L, and NiII-L, the CuII-L complex inhibits breast cancer cell growth more effectively. Furthermore, the PTHAC ligand was successfully applied for separation via flotation and spectrophotometric determination of Co(II) in several natural water, certified ore and pharmaceutical samples using oleic acid surfactant (HOL). At pH 6.5, PTHAC reacted with Co(II) to create a dark green (1:1) Co(II):PTHAC complex that was floated significantly using oleic acid (HOL) surfactant. The different experimental variable affecting the separation procedure e.g. pH, concentration of Co(II), HOL, PTHAC, temperature etc.…, were investigated. Co(II) had a linear range of (0.1–7.0) mgL−1. In the aqueous and scum layers, the molar absorptivities for the coloured complex are 0.14 × 104 and 0.16 × 105Lmol−1 cm−1, respectively. The LOD was 0.04 mgL−1, which is related to Sandell sensitivity of 3.7 × 10−3 µg cm−2 with a preconcentration factor of 200 and a RSD, % (n = 5) less than 4.2%. In addition, the mechanisms involved in the process of coordination of PTHAC with Cu(II), Co(II) and Ni(II) and the mechanism involved in the process of flotation of the PTHAC-Co(II) complex using HOL surfactant were elucidated.

show abstract

Temperature, medium and structural effects on the acid dissociation constants of certain Schiff bases derived from isatin with some amino acids and aroylhydrazines

Cited by 2 publications

References 11 publications

Acid Dissociation Constants of Some Novel Isatin Thiosemicarbazone Derivatives

Acid Dissociation Constants of Some Novel Isatin Thiosemicarbazone Derivatives

Design, spectral, molecular modeling, antimitotic, analytical and mechanism studies of phenyl isothiocyanate Girard's T derived metal complexes

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