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

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

Synthesis and the crystal and molecular structures of (H3 L • Cl)[CoCl4] and H2 L[CuBr4] (L is 2,4,6-Tri(N,N-dimethylamino)methylphenol)

The complex compounds (H3 L • Cl)[CoCl4] (I) and H2 L[CuBr4] (II), where L is 2,4,6-tri(N,N-dimethylamino) methylphenol, were isolated in the crystalline state and studied by X-ray diffraction. The organic cations were found to be outer-sphere ligands. All three nitrogen atoms of the tertiary amino groups are protonated. In compound I, the H3 L 3+ cation exists as the cis tautomer. In compound II, the H2 L 2+ dication exists as the trans isomer. In the crystal structure, the dications are arranged in layers via hydrogen bonds. © 2010 Pleiades Publishing, Ltd

Synthesis and the crystal and molecular structures of (H3 L • Cl)[CoCl4] and H2 L[CuBr4] (L is 2,4,6-Tri(N,N-dimethylamino)methylphenol)

The complex compounds (H3 L • Cl)[CoCl4] (I) and H2 L[CuBr4] (II), where L is 2,4,6-tri(N,N-dimethylamino) methylphenol, were isolated in the crystalline state and studied by X-ray diffraction. The organic cations were found to be outer-sphere ligands. All three nitrogen atoms of the tertiary amino groups are protonated. In compound I, the H3 L 3+ cation exists as the cis tautomer. In compound II, the H2 L 2+ dication exists as the trans isomer. In the crystal structure, the dications are arranged in layers via hydrogen bonds. © 2010 Pleiades Publishing, Ltd

Crystal and molecular structures of 3-amino-4-hydroxy benzenesulfonamide and its hydrochloride: Quantum-chemical study of their tautomerism

3-amino-4-hydroxy benzenesulfonamide and its hydrochloride have been isolated in the crystalline state. Their crystal and molecular structures are determined by X-ray diffraction. The equilibrium between neutral tautomeric forms of the 3-amino-4-hydroxy benzenesulfonamide molecule is studied within the approximation of density functional theory (B3LYP/aug-cc-pVDZ). The constants of acid-base equilibrium of 3-amino-4-hydroxy benzenesulfonamide are deter-mined using spectrophotometry. © 2013 Pleiades Publishing, Ltd

Crystal and molecular structures of 3-amino-4-hydroxy benzenesulfonamide and its hydrochloride: Quantum-chemical study of their tautomerism

3-amino-4-hydroxy benzenesulfonamide and its hydrochloride have been isolated in the crystalline state. Their crystal and molecular structures are determined by X-ray diffraction. The equilibrium between neutral tautomeric forms of the 3-amino-4-hydroxy benzenesulfonamide molecule is studied within the approximation of density functional theory (B3LYP/aug-cc-pVDZ). The constants of acid-base equilibrium of 3-amino-4-hydroxy benzenesulfonamide are deter-mined using spectrophotometry. © 2013 Pleiades Publishing, Ltd

Complex compounds of Some p, d, and f metals with 2,4,6-Tris(N,N- dimethylaminomethyl)phenol (HL): Crystal and molecular structure of H 4L(NO3)3 · H2O and H 4LCl3 · 3H2O

Eight aluminum, cobalt(II), copper(II), cadmium, samarium(III), and europium(III) complexes with 2,4,6-tris(N,N-dimethylaminomethyl)phenol (HL) were isolated in the crystalline state and studied by physicochemical methods (IR and UV-Vis spectroscopy, potentiometry). The complexation processes of sin- gly, doubly, and triply charged metal ions with HL were studied by spectrophotometry and potentiometry, the composition of complexes was determined, and the stability constants were calculated. The crystal and molecular structures of 2,4,6-tris(N,N-dimethylaminomethyl)phenol trichloride and trinitrate H 4L(NO3)3 · H2O and H 4LCl3 · 3H2O were studied by X-ray diffraction. © Pleiades Publishing, Ltd., 2011

Complex compounds of Some p, d, and f metals with 2,4,6-Tris(N,N- dimethylaminomethyl)phenol (HL): Crystal and molecular structure of H 4L(NO3)3 · H2O and H 4LCl3 · 3H2O

Eight aluminum, cobalt(II), copper(II), cadmium, samarium(III), and europium(III) complexes with 2,4,6-tris(N,N-dimethylaminomethyl)phenol (HL) were isolated in the crystalline state and studied by physicochemical methods (IR and UV-Vis spectroscopy, potentiometry). The complexation processes of sin- gly, doubly, and triply charged metal ions with HL were studied by spectrophotometry and potentiometry, the composition of complexes was determined, and the stability constants were calculated. The crystal and molecular structures of 2,4,6-tris(N,N-dimethylaminomethyl)phenol trichloride and trinitrate H 4L(NO3)3 · H2O and H 4LCl3 · 3H2O were studied by X-ray diffraction. © Pleiades Publishing, Ltd., 2011

Trinitrotoluene as a precursor in synthesis of effective azodyes and azopygments

The results of investigations of chemical transformations of trinitrotoluene and trinitrobenzene into azodyes and azopygments are presented. About 90 new ammino- and azocompounds were synthezised and investigated by a set of spectroscopic and theoretical methods and tested as acid and disperse dyes with high resistance to physical and chemical treatments

Trinitrotoluene as a precursor in synthesis of effective azodyes and azopygments

The results of investigations of chemical transformations of trinitrotoluene and trinitrobenzene into azodyes and azopygments are presented. About 90 new ammino- and azocompounds were synthezised and investigated by a set of spectroscopic and theoretical methods and tested as acid and disperse dyes with high resistance to physical and chemical treatments