In this study, four arylazobenzylidene dyes (a-d) were synthesized with excellent yields in two steps using Knoevenagel condensation and azo-coupling reactions. Absorption spectra of these dyes with different substituents were investigated in organic solvents as a function of solvent polarity. The spectral features of synthesized arylazobenzylidene dyes were described according to azo-hydrazone...

The protonation constants of alanine and alanine methyl ester were determined in different aqueous solutions of 1,4-dioxane containing (0-50% v/v), using a potentiometric method at 25o C and constant ionic strength 0.1 mol.L-1 (NaCl). The protonation constants were analyzed in terms of Kamlet, Abboud and Taft (KAT) parameters. The results show that the effect of β is higher in comparison with t...

A series of five tetracyclic mono azo dyes based on the diazotization 1-amino-8-hydroxynaphthalene-3,6-disulphonic acid and subsequent coupling with substituted (un)sulphonated naphthalene derivatives have been synthesized. The chemical structures were established using UV–visible, IR, NMR as well mass spectrometry. Based number sulphonic other hydrophilic groups they contain, compounds showed ...

A novel series of the title compound 4-(5-arylazo-2-hydroxystyryl)-1-methylpyridinium iodide 6 has been synthesized via condensation reactions of the arylazosalicylaldehyde derivatives 4a-i with 1-methyl-picolinium iodide 5. The structures of the new arylazo compounds were characterized by ¹H NMR, IR, mass spectroscopy, as well as spectral and elemental analyses. The electronic absorption spect...

The binding energies of 121 complexes between anions and bis(cyclopeptides) differing in the structure number linking units two cyclopeptide rings were analyzed. These Gibbs free obtained earlier work for different anions, under conditions, with methods. multiparametric analysis a subset 42 afforded linear relationships that allowed relatively reliable estimation iodide sulfate affinity three s...

The protonation constants of glycine, L-alanine, glycyl-glycine, glycyl-glycyl-glycine and glycyl-L-alanine have been determined in 10-80% (v/v) ethanol-water mixtures at 25 °C and constant ionic strength (0.1 mol L-1 sodium perchlorate), by potentiometric technique and calculated using a suitable computer program, which employs a nonlinear least-squares method. The effect of solvent compositio...

A quantitative study of the variation of the conformational equilibria of 7-benzyl-2-iodo-9-oxa-7-azabicyclo[4.3.0]nonan-8-one 1 in 10 solvents has been carried out. The experimental composition in each solvent has been obtained from experimental NMR vicinal H-H coupling constants together with molecular modeling. The solvent properties, particularly polarity and hydrogen bonding ability, were ...

A convenient and efficient approach toward the synthesis of seven aromatically substituted xanthendiones (1?7) one structurally-related xanthenone (8) through condensation dimedone appropriate aromatic aldehyde is reported. Further, their chemical structure was confirmed by melting points, elemental analysis, FT-IR, 1H, 13C NMR UV-Vis spectroscopic methods. The relationship between pharmacologi...

Abstract Wax by-products from commercial Cannabis processing, containing between 41 and 46% (w/w) cannabinoids, are currently underutilized due to lack of research done, significant value can be added through recovery the cannabinoids. The cannabinoids aimed recovered via a novel solvent-assisted recrystallization technology, this study provides robust solvent screening methodology for technolo...

This work aimed to the study effect of ethanol ratios on acidity constants bromocresol purple. The BCP were determined in binary mixtures water with containing 0, 30, 40, 50, 60, and 70% (v/v) using spectrophotometric methods. results indicate dependence ratio ethanol. values log10Ka1 log10Ka2 correlated macroscopic (relative permittivity, ε) microscopic Kamlet–Taft parameters (α, β, π*) mixtur...