Thermal properties of some biologically active 5-(p-substituted phenylazo)-6-aminouracil complexes

Masoud, Mamdouh S.; El-Enein, Saeyda A. Abou; Ramadan, Ahmed M.; Goher, A.S.

doi:10.1016/j.jaap.2007.08.002

Cited by 34 publications

(7 citation statements)

References 29 publications

(32 reference statements)

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“…in a less random molecular configuration than the reacting complexes. Moreover, the fraction appeared in the calculated order of the thermal reactions (n), confirmed that the reactions proceeded in complicated mechanisms …”

Section: Resultsmentioning

confidence: 69%

Molecular modeling, spectral investigation and thermal studies of the new asymmetric Schiff base ligand; (E)‐N'‐(1‐(4‐((E)‐2‐hydroxybenzylideneamino)phenyl)ethylidene)morpholine‐4‐carbothiohydrazide and its metal complexes: Evaluation of their antibacterial and anti‐molluscicidal activity

El-Samanody

Abouel‐Enein

Emara

2018

Applied Organom Chemis

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A new tetradentate asymmetric Schiff base ligand; (E)-N'-(1-(4-((E)-2hydroxybenzylideneamino)phenyl)ethylidene)morpholine-4-carbothiohydrazide (H 2 L) was prepared by consecutive condensation reactions between p-aminoacetophenone, salicylaldehyde and 4-morpholinethiosemicarbazide. The structures of the obtained ligand along with its Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Cr(III), Fe(III) and Ru(III) complexes were authenticated by different analytical and spectral techniques. The ligand behaves as a monobasic tetradentate one and chelates with metal ions through the deprotonated phenolic oxygen, imine nitrogen, thione sulfur and azomethine nitrogen atoms (ONNS chromophore). All nonelectrolyte metal complexes possess octahedral geometry, except Ni(II) and Cu(II) complexes (2, 3) which have tetra-coordinate structures. The thermal stability of metal complexes is higher than that of the free ligand and the general thermal degradation pathways were discussed based on thermogravimetric technique. The activation thermodynamic parameters as well as the order of reaction (n) were estimated from DTG curves by using Piloyan method. Thermogravimetric analyses and mass spectra of metal complexes confirm the number of solvents in their inner and outer spheres.Molecular modeling data were used to demonstrate the thermal decomposition pathways of the ligand and its metal complexes, confirming their chemical structures. The ESR spectra of Cu(II) complexes indicate that the unpaired electron is localized mainly in the d (x 2 -y 2 ) orbital with axial symmetry. Powder X-ray diffraction analyses for Co(II), Cu(II) and Ru(III) complexes (1,3,7) show that copper complex has a crystalline nature, whereas, cobalt and ruthenium complexes are amorphous. The ligand and its metal complexes were tested in vitro for their anti-molluscicidal activity against Eobania vermiculata. The results reveal that the investigated compounds have remarkable antimolluscicidal activities against the tested land snail with various sensitivity levels. The synthesized compounds were also screened in vitro for their

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Section: Resultsmentioning

confidence: 69%

Molecular modeling, spectral investigation and thermal studies of the new asymmetric Schiff base ligand; (E)‐N'‐(1‐(4‐((E)‐2‐hydroxybenzylideneamino)phenyl)ethylidene)morpholine‐4‐carbothiohydrazide and its metal complexes: Evaluation of their antibacterial and anti‐molluscicidal activity

El-Samanody

Abouel‐Enein

Emara

2018

Applied Organom Chemis

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“…When the two decomposition pathways of the two complexes were followed, some trends and observations may be noted. The dehydration/desolvation processes started at a low temperature within a broad temperature range (19–429°C) with an estimated mass loss of 6.7 and 9.39% for Co(II) and Ni(II) complexes, respectively. The lower onset temperature (19°C) of dehydration/desolvation stage, associated with the extended temperature range, points to the fact that the solvents of crystallization have different crystalline nature and they are distributed in the crystal voids where these molecules do not have any role in the lattice forces .…”

Section: Resultsmentioning

confidence: 99%

Coordination Behavior of N‐Donor Schiff Base Derived from 2‐Benzoylpyridine Toward Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), and Cr(III) Metal Ions: Synthesis, Spectroscopic and Thermal Studies, and Biological Activity

Emam

Abouel‐Enein

El-Seady

2017

J Chinese Chemical Soc

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A new Schiff base was prepared from the reaction of 4,4 0 -methylenedianiline with 2benzoylpyridine in 1:2 molar ratio, as well as its different metal chelates. The structures of the ligand and its metal complexes were studied by elemental analyses, spectroscopic methods (infrared [IR], ultraviolet-visible [UV-vis], 1 H nuclear magnetic resonance [NMR], electron spin resonance [ESR]), magnetic moment measurements, and thermal studies. The ligand acts as tetradentate moiety in all complexes. Octahedral geometry was suggested for Mn(II), Cu(II), Cr(III), and Zn(II) chloride complexes and pentacoordinated structure and square planar geometry for Co(II), Ni(II), Cu(NO 3 ) 2 , CuBr 2 , and Pd(II) complexes. ESR spectra of copper(II) complexes (4)-(6) at room temperature display rhombic symmetry for complex (4) and axial type symmetry for complexes (5) and (6), indicating d x 2y 2 1 ground state for Cu(II) complexes. The derivative thermogravimetric (DTG) curves of the ligand and its metal complexes were analyzed by using the rate equation to calculate the thermodynamic and kinetic parameters, which indicated strong binding of the ligand with the metal ion in some complexes. Also, some of these compounds were screened to establish their potential as anticancer agents against the human hepatic cell line Hep-G 2 . The obtained IC 50 value of the copper(II) bromide complex (4.34 μg/mL) is the highest among the compounds studied. Biological studiesA preliminary investigation of antitumor activity of ligand L and some of its metal complexes (4-7, 9) was carried out against human hepatic cell line Hep-G 2 at the Regional Center for Mycology and Biotechnology, Al-262 www.jccs.wiley-vch.de JOURNAL OF THE CHINESE CHEMICAL SOCIETYPhysiochemical studies of transition metal complexes of 2-benzoylpyridine Schiff base Scheme 6. TG weight losses of Cr(III) complex (8). Scheme 5. TG weight losses of Mn(II) complex (1). JOURNAL OF THE CHINESE CHEMICAL SOCIETYPhysiochemical studies of transition metal complexes of 2-benzoylpyridine Schiff base Scheme 7. TG weight losses of Cu(II) bromide complex (5).

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“…All the change of entropy values, ΔS have -ve signs which indicate that the activated transition states are more ordered, i.e. in a less random molecular configuration than the reacting complexes [25][26][27][28][29][30].…”

Section: 𝑪𝒑mentioning

confidence: 99%

Thermal behavior and thermodynamic parameters of some complexes of biologically active nucleic acid constituents

Masoud¹,

Ramadan²,

Sweyllam³

et al. 2021

World J. Adv. Res. Rev.

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The thermal behavior of some complexes derived from biologically nucleic acid constituents has been studied applying differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. Thermodynamic parameters, decompositions and thermal stabilities are calculated and explained. All the complexes gave exothermic peaks with -ve signs for change of entropy values, ΔS which indicate that the activated transition states are more ordered, i.e. in a less random molecular configuration than the reacting complexes. TGA gives the mechanism of decomposition.

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Thermal properties of some biologically active 5-(p-substituted phenylazo)-6-aminouracil complexes

Cited by 34 publications

References 29 publications

Coordination Behavior of N‐Donor Schiff Base Derived from 2‐Benzoylpyridine Toward Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), and Cr(III) Metal Ions: Synthesis, Spectroscopic and Thermal Studies, and Biological Activity

Thermal behavior and thermodynamic parameters of some complexes of biologically active nucleic acid constituents

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