Organic chemistry
Nader Noroozi Pesyan; Vali Gholsanamloo; Maryam Moradi Par; Hamid Rashidnejad; Ali Gharib; Kamelia Nejati
Abstract
Four new azo-dyes, 3-phenyl azopentane-2,4-dion (LA), 3-(4-nitro phenyl azo)-pentane-2,4-dion (LP), 3-(2-nitro phenyl azo)-pentane-2,4-dion (LO) and 4-(1-acetyle-2-oxo-propyl azo)-benzene sulfonate sodium (LS), were synthesized from, aniline, 4-nitroaniline, 2-nitroaniline and sulfanilic acid with acetylacetone, ...
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Four new azo-dyes, 3-phenyl azopentane-2,4-dion (LA), 3-(4-nitro phenyl azo)-pentane-2,4-dion (LP), 3-(2-nitro phenyl azo)-pentane-2,4-dion (LO) and 4-(1-acetyle-2-oxo-propyl azo)-benzene sulfonate sodium (LS), were synthesized from, aniline, 4-nitroaniline, 2-nitroaniline and sulfanilic acid with acetylacetone, respectively. Reaction of these new dyes with acetate salts of copper(II), nickel(II) and cobalt(II) in molar ratios of 1:2 were carried out to produce azo metal (II) complexes with the general stoichiometry; CuL2, CoL2 and NiL3 in complexes. Structure of azo dyes was characterized using FT-IR,1H NMR,13C NMR, UV-Visible and also the corresponding metal (II) complex were characterized by FT IR, UV-Visible and CHN and XRD analysis techniques. Elemental analysis and spectral data indicated that the dye as a ligand with two teeth, N and O, acts as a bidentate ligand. Differences in absorption maxima of azo ligands compared to those corresponding complexes were also studied. Also, in this work, singular value decomposition (SVD) as a chemometric method was used to determine the Cu(II), Co(II) and Ni(II) complexes with the mentioned ligands in methanol by UV-Vis spectrophotometry. SVD method confirmed the formation of CuL2, CoL2 and NiL3 complexes.
Physical chemistry
Nasrin Sohrabi; Maryam Dookheh
Volume 3, Issue 3, pp. 180-282,Serial No. 8 , July 2015, , Pages 254-265
Abstract
In this study at first , an azo dye, 2,7- naphthalenediol, 2-[(4-Bromophenyl)azo (BPAND) as a ligand has been synthesized by addition of p-Bromoaniline to the modified montomorillonite K10 clay. This ligand was characterized using 1H-NMR, UV-Vis and IR spectroscopies. Subsequently, its interaction with ...
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In this study at first , an azo dye, 2,7- naphthalenediol, 2-[(4-Bromophenyl)azo (BPAND) as a ligand has been synthesized by addition of p-Bromoaniline to the modified montomorillonite K10 clay. This ligand was characterized using 1H-NMR, UV-Vis and IR spectroscopies. Subsequently, its interaction with calf thymus deoxyribonucleicacid ,ct-DNA was investigated in 5 mM phosphate buffer solution, pH=7 using UV-Vis absorption, thermal denaturation and viscosity measurement. From spectrophotometric titration experiments, the binding constant of BPAND with ct-DNA was found to be (2.89±0.2)×107 M-1 at 25°C. In order to determine changes in thermodynamic properties such as binding constant, Gibbs free energy, binding enthalpy and binding entropy, this experiment was done at various temperatures. The enthalpy and entropy changes were -2.852±0.634 kJ/mol and -814.065 ±2.52 J/mol.K, respectively.Thermal denaturation experiments show the increasing of melting temperature of ct-DNA (about 0.06°C less than 0.6) due to binding of BPAND ligand. From these results the mechanism and the stoichiometry of binding were determined. The results revealed that this interaction is exothermic (negative enthalpy change) along with negative entropy change. Therefore, the driving force in these interactions is enthalpy and the process is enthalpy-driven and suggest that the main driving force for the ct-DNA-BPAND complex formation is being Van der Waals or hydrogen binding.
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