Synthesis, characterization, and application of novel aryldiazenyl disperse dyes on polyester fabrics.

Azo dyes are widely used for dyeing polyester fabrics but require optimization of properties like color strength and fastness. Fourteen novel disperse azo dyes were synthesized from 2,3-naphthalenediol and aniline derivatives to examine their potential for polyester dyeing. The dyes were prepared via diazotization and coupling reactions and characterized using FT-IR, UV-Vis, 1H NMR, 13C NMR, and elemental analysis. Furthermore, several techniques were employed to study the azo-hydrazone tautomerism, including UV-Vis spectroscopy, NMR spectroscopy, and computational methods. DFT computations revealed hydrazone tautomers were more stable than azo tautomers. The prepared azo dyes were applied on polyester fabrics at 2% depth using a high temperature pressure technique in water utilizing DYEWELL-002 as a dispersing agent. The color shading of dyed polyester samples ranged from peach amber to apple of my eye, depending on the coupler moieties. The fastness properties, assessed using a grey scale of dyed polyester fabrics, indicated very good to excellent grades for most dyes. Additionally, measurements of color strength (K/S), dye exhaustion (%E), as well as colorimetric colors CILAB of dyed polyester fabrics values, were measured and discussed in terms of the effect of substituents. The findings provide new insights into structure-performance relationships to design optimized disperse dyes for polyester coloration. Overall, the synthesized aryldiazenyl dyes are promising candidates for dyeing polyester fabrics across a spectrum of shades with good fastness properties.

Synthesis, spectroscopic characterization and dyeing performance of novel bis azo dyes derived from benzidine.

Benzidine was coupled with ethyl cyanoacetate, and malononitrile, to give azo-hydrazo products which in turn were cyclized by using hydrazine and phenyl hydrazine to give 4,4'-([1,1'-biphenyl]-4,4'-diylbis(hydrazin-2-yl-1-ylidene))bis pyrazole derivatives 5-7. These compounds were identified by various spectral analysis. The examination of 0.1 M NaOH and 0.1 M HCl in DMF revealed that the λmax of the synthesized dyes are quite sensitive to pH variation and slightly affected by the coupler moieties. Utilizing the dispersion agent DYEWELL-002, polyester fabric (PE-F) was dyed in water. The color strength (K/S), its summation (K/Ssum), dye exhaustion (%E) and reflectance values were measured and discussed. The DFT method estimates the chemical descriptor parameters of the titled dyes, using B3LYP/6-31G(d,p) level to investigate the performance of dyes as well as to postulate a mechanism of dyeing process.

Synthesis and Antimicrobial Activity Screening of Piperazines Bearing N,N'-Bis(1,3,4-thiadiazole) Moiety as Probable Enoyl-ACP Reductase Inhibitors.

A new N,N'-disubstituted piperazine conjugated with 1,3,4-thiadiazole and 1,2,4-triazole was prepared and the chemical structures were identified by IR, NMR and elemental analysis. All the prepared compounds were tested for their antimicrobial activity. The antimicrobial results indicated that the tested compounds showed significant antibacterial activity against gram-negative strains, especially E. coli, relative to gram-positive bacteria. Docking analysis was performed to support the biological results; binding modes with the active site of enoyl reductase amino acids from E. coli showed very good scores, ranging from -6.1090 to -9.6184 kcal/mol. Correlation analysis was performed for the inhibition zone (nm) and the docking score.