Experimental and Theoretical Investigations of Complex Formation of Substituted Phenylazo-Derivatives of Methylphloroglucinol

Using spectrophotometric titration technique, the processes of complex formation of some phenylazo-derivatives of methylphloroglucinol (MPG) containing hydroxo-, nitro- and nitroso-substituents were studied. The spectral criteria of neutral and ionized forms of the organic ligands in their different tautomeric forms were determined.It was detected that the complex formation is accompanied by formation of one or two chelate cycles which involve azo- or nitroso-fragments and neighboring OH-groups of the organic ligands. Different types of coordination lead to different changes in the electronic absorption spectra.The DFT-B3LYP modeling of a Ni(II) complex of α-hydroxyphenylazo MPG established the most probable coordination mode of the organic ligand: tridentate chelating dianion, distorted square coordination of Ni-cations including one water molecule. The theoretical results are in a good accordance with the experimental data.

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Experimental and Theoretical Investigations of Complex Formation of Substituted Phenylazo-Derivatives of Methylphloroglucinol

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v4i1.957 ◽

2008 ◽

Vol 4 (1) ◽

pp. 295-300

Author(s):

Olga Kovalchukova ◽

Amangdam A.T. ◽

Strashnova S.B. ◽

Strashnov P.V. ◽

Romashkina E.P. ◽

...

Keyword(s):

Complex Formation ◽

Organic Ligand ◽

Spectrophotometric Titration ◽

Organic Ligands ◽

Oh Groups ◽

Tautomeric Forms ◽

Theoretical Investigations ◽

Derivatives Of ◽

Theoretical Results ◽

Titration Technique

Using spectrophotometric titration technique, the processes of complex formation of some phenylazo-derivatives of methylphloroglucinol (MPG) containing hydroxo-, nitro- and nitroso-substituents were studied. The spectral criteria of neutral and ionized forms of the organic ligands in their different tautomeric forms were determined.It was detected that the complex formation is accompanied by formation of one or two chelate cycles which involve azo- or nitroso-fragments and neighboring OH-groups of the organic ligands. Different types of coordination lead to different changes in the electronic absorption spectra.The DFT-B3LYP modeling of a Ni(II) complex of α-hydroxyphenylazo MPG established the most probable coordination mode of the organic ligand: tridentate chelating dianion, distorted square coordination of Ni-cations including one water molecule. The theoretical results are in a good accordance with the experimental data.

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The Spectroscopic and theoretical investigations of complex formation of (3E,3'E)-7,7'-(carbonylbis(azanediyl))bis(3-(2-(2-hydroxyphenyl)hydrazono)-4-oxo-3,4-dihydronaphthalene-2-sulfonic acid) with metal cations

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v15i2.7500 ◽

2018 ◽

Vol 15 (2) ◽

pp. 6207-6217

Author(s):

Olga Kovalchukova ◽

Mikhael Ryabov ◽

Alexandra Obmenennaya ◽

Nikolai Popandopulo

Keyword(s):

Complex Formation ◽

Mass Spectra ◽

Coupling Reaction ◽

Metal Cations ◽

Spectrophotometric Titration ◽

Vis Spectroscopy ◽

Diazo Coupling ◽

Theoretical Investigations ◽

Diazo Coupling Reaction ◽

Charge Calculations

A novel azo-dye was isolated by a diazo-coupling reaction and characterized by the elemental analysis, mass spectra, IR and UV-VIS spectroscopy. The processes of complex formation of H4L with some mono-, bis-, and trivalent metal cations were studied by spectrophotometric titration and theoretical modeling. The NBO effective charge calculations indicate a strong covalent character of the coordination bonds at complexation.

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Roles of Organic Fragments in Redirecting Crystal/Molecular Structures of Inorganic–Organic Hybrids Based on Lacunary Keggin-Type Polyoxometalates

Molecules ◽

10.3390/molecules26195994 ◽

2021 ◽

Vol 26 (19) ◽

pp. 5994

Author(s):

Ruhollah Khajavian ◽

Vida Jodaian ◽

Fatemeh Taghipour ◽

Joel T. Mague ◽

Masoud Mirzaei

Keyword(s):

Organic Ligand ◽

Molecular Structures ◽

Organic Ligands ◽

Keggin Type ◽

Self Assembling ◽

Behavioral Studies ◽

Structures And Properties ◽

Derivatives Of ◽

Organic Fragment

Lacunary polyoxometalates (LPOMs) are key precursors for the synthesis of functional POMs. To date, reviews dedicated to behavioral studies of LPOMs often comprise the role of metal ions, including transition metal (TM) and rare earth (RE) ions, in extending and stability of high-nuclearity clusters. In contrast, the role of organic ligands in the structures and properties of lacunary-based hybrids has remained less explored. In this review, we focus on the role of organic fragments in the self-assembling process of POM-based architectures and discuss relationships between the nature and structure of organic ligand and properties such as the topology of hybrid inorganic–organic material in RE and TM-RE heterometallic derivatives of lacunary Keggin-type POMs. The effects of organic fragment in mixed ligand hybrids are also briefly reviewed.

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ANALYSIS OF THE GENERAL EQUATIONS OF THE TRANSVERSE VIBRATION OF A PIECEWISE UNIFORM VISCOELASTIC PLATE

Computational nanotechnology ◽

10.33693/2313-223x-2020-7-3-52-56 ◽

2020 ◽

Vol 7 (3) ◽

pp. 52-56

Author(s):

MMATMATISA JALILOV ◽

◽

RUSTAM RAKHIMOV ◽

Keyword(s):

Cross Section ◽

Transverse Vibration ◽

Three Dimensional ◽

Viscoelastic Plate ◽

Constant Thickness ◽

Regional Problem ◽

Rigid Contact ◽

Under Construction ◽

Derivatives Of ◽

Theoretical Results

This article discusses the analysis of the general equations of the transverse vibration of a piecewise homogeneous viscoelastic plate obtained in the “Oscillation of inlayer plates of constant thickness” [1]. In the present work on the basis of a mathematical method, the approached theory of fluctuation of the two-layer plates, based on plate consideration as three dimensional body, on exact statement of a three dimensional mathematical regional problem of fluctuation is stood at the external efforts causing cross-section fluctuations. The general equations of fluctuations of piecewise homogeneous viscoelastic plates of the constant thickness, described in work [1], are difficult on structure and contain derivatives of any order on coordinates x, y and time t and consequently are not suitable for the decision of applied problems and carrying out of engineering calculations. For the decision of applied problems instead of the general equations it is expedient to use confidants who include this or that final order on derivatives. The classical equations of cross-section fluctuation of a plate contain derivatives not above 4th order, and for piecewise homogeneous or two-layer plates the elementary approached equation of fluctuation is the equation of the sixth order. On the basis of the analytical decision of a problem the general and approached decisions of a problem are under construction, are deduced the equation of fluctuation of piecewise homogeneous two-layer plates taking into account rigid contact on border between layers, and also taking into account mechanical and rheological properties of a material of a plate. The received theoretical results for the decision of dynamic problems of cross-section fluctuation of piecewise homogeneous two-layer plates of a constant thickness taking into account viscous properties of their material allow to count more precisely the is intense-deformed status of plates at non-stationary external loadings.

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Hydrogen bonds in derivatives of N-substituted N’-benzoyl- and N’-(2-chlorobenzoyl)thiourea

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19910880 ◽

1991 ◽

Vol 56 (4) ◽

pp. 880-885 ◽

Cited By ~ 4

Author(s):

Oľga Hritzová ◽

Dušan Koščík

Keyword(s):

Hydrogen Bonds ◽

Spectral Studies ◽

Intramolecular Hydrogen Bonds ◽

Tautomeric Forms ◽

Intramolecular Hydrogen ◽

Derivatives Of

Intramolecular hydrogen bonds of the N-H···O=C type have been detected in the derivatives of N-substituted N’-benzoyl- and N’-(2-chlorobenzoyl)thiourea on the basis of IR spectral studies. The title compounds can exist in two tautomeric forms.

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An Assessment of the Value of Theory in Predicting Gas-Bearing Performance

Journal of Basic Engineering ◽

10.1115/1.3658924 ◽

1961 ◽

Vol 83 (2) ◽

pp. 195-200 ◽

Cited By ~ 1

Author(s):

S. Cooper

Keyword(s):

Steady State ◽

Slip Velocity ◽

Reynolds Equation ◽

Energy Equation ◽

Experimental Methods ◽

Experimental Results ◽

Theoretical Investigations ◽

Gas Bearing ◽

Theoretical Results

The object of the paper is to indicate the value of theoretical investigations of hydrodynamic finite bearings under steady-state conditions. Methods of solution of Reynolds equation by both desk and digital computing, and methods of stabilizing the processes of solution, are described. The nondimensional data available from the solutions are stated. The outcome of an attempted solution of the energy equation is discussed. A comparison between some theoretical and experimental results is shown. Experimental methods employed and some difficulties encountered are discussed. Some theoretical results are given to indicate the effects of the inclusion of slip velocity, stabilizing slots, and a simple case of whirl.

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Complex formation between derivatives of pyridine N-oxides and iron(III) nitrate in aqueous medium

Russian Journal of General Chemistry ◽

10.1134/s1070363216010163 ◽

2016 ◽

Vol 86 (1) ◽

pp. 92-95

Author(s):

A. V. Ryzhakov ◽

V. P. Andreev

Keyword(s):

Complex Formation ◽

Aqueous Medium ◽

Derivatives Of

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The synthesis of the isomeric N-methyl derivatives of murexine

Australian Journal of Chemistry ◽

10.1071/ch9811739 ◽

1981 ◽

Vol 34 (8) ◽

pp. 1739 ◽

Cited By ~ 8

Author(s):

CC Duke ◽

JV Eichholzer ◽

JK Macleod

Keyword(s):

Imidazole Ring ◽

The Other ◽

Pharmacological Activities ◽

Tautomeric Forms ◽

Methyl Derivatives ◽

Paramagnetic Ions ◽

Nucella Emarginata ◽

Derivatives Of

The two isomeric N-methyl derivatives of murexine have been synthesised by independent routes and shown to be different from an 'N- methylmurexine' reportedly isolated from the mollusc Nucella emarginata. 1H n.m.r. studies have shown a marked difference in the extent of binding to paramagnetic ions of the two N-methyl derivatives of murexine in water while pharmacological results show substantially different pharmacological activities of the two isomers. Both results can be rationalized in terms of the observed activities being associated with the presence of one or the other of the tautomeric forms of the imidazole ring.

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A Novel Synthetic Approach to Asymmetric Salen, Dihydrosalen, and Tetrahydrosalen Ligands: Structures and O2-Activating Properties of their Nickel(II) and Cobalt(II) Complexes

Zeitschrift für Naturforschung B ◽

10.1515/znb-1994-0814 ◽

1994 ◽

Vol 49 (8) ◽

pp. 1089-1100 ◽

Cited By ~ 24

Author(s):

Arnd Böttcher ◽

Horst Elias ◽

Brigitte Eisenmann ◽

Elke Hilms ◽

Andreas Huber ◽

...

Keyword(s):

Equilibrium Constants ◽

Spectrophotometric Titration ◽

Acetone Solution ◽

Synthetic Approach ◽

Coordination Core ◽

Type Complex ◽

Square Planar ◽

Synthetic Procedure ◽

Derivatives Of ◽

Methyl Phenyl

A synthetic procedure is described for the preparation of the tetradentate N2O2 ligands H2[H4]L1=6-(2-hydroxyphenyl)-2,5-diaza-3,3-dimethyl-1-(2-hydroxy-3-t-butyl-5-methyl- phenyl)heptane, H2[H2]L1 = 6-(2-hydroxyphenyl)-2,5-diaza-3,3-dimethyl-1-(2-hydroxy-3-t-butyl-5-methylphenyl)-1-heptene, and H2L1 = 6-(2-hydroxyphenyl)-2,5-diaza-3,3-dimethyl-1-(2- hydroxy-3-t-butyl-5-methylphenyl)-1,5-heptadiene, which are asymmetric derivatives of the ligands tetrahydrosalen, dihydrosalen, and salen. Complexes Ni[H4]L1, Ni[H2]L1, NiL1, CoL1, Ni[H4]L2 (([H4]L2)2- = anion of H2[H4]L2 = N,N'-bis(2-hydroxy-3-t-butyl-5-methylbenzyl)- trans-(S,S)-1,2-diaminocyclohexane), and NiL2 were prepared, characterized (VIS and IR absorption, magnetic moment) and subjected to spectrophotometric titration with pyridine, to determine the equilibrium constants for adduct formation. Single crystal X-ray structure analyses were carried out for Ni[H2]L1 (monoclinic, P21/n; a = 8.926(4), b = 29.324(7), c = 8.411(4) Å; β = 95.3(1)°; Z = 4), CoL1 (monoclinic, C2/c; a = 25.389(2), b = 18.139(2), c = 10.179(1) Å; β = 112.227(6); Z = 8), and Ni[H4]L2·acetone (tetragonal, P41212; a = 13.928(3), c = 33.698(5) Å; Z = 8). In all of the three complexes, the N2O2-metal coordination core is square-planar. The skeleton of the tetradentate ligand is more or less twisted. The planar cobalt(II) complex CoL1 is a low spin d7 system with μexp = 2.02 BM at 298 K, whereas the planar complexes NiL1, Ni[H2]L1 and Ni[H4]L2 are diamagnetic (μexp = 0.28-0.64 BM). The blue solvate Ni[H4]L1- 3EtOH · H2O is paramagnetic (μexp = 3.04 BM), which points to octahedral coordination. In aerated acetone solution, the tetrahydrosalen-type complex Ni[H4]L1 activates dioxygen and one C-N bond is oxidatively dehydrogenated. The VIS spectrum of the dihydrosalen-type complex formed is virtually identical with that of the aldimine complex Ni[H2]L1. In the presence of dioxygen, Co[H4]L1 and Co[H2]L1 are readily oxidized to CoL1 in acetone solution.

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