Synthesis,Structures,Spectra And Dyeing Performance Of Sulfur-containing Heterocyclic Disperse Dyes

Azo dyes are one of the most important categories of synthetic dyes because they are easily synthesized.They have been widely used in traditional textile industry due to their wide variety of color shades and brilliant colors.In addition,they also have potential wide applications in many other fields such as non-linear optics,optical data storage,two proton absorptions,ink jet,printersmetallochromic indicatorsand and dye-sensitized solar cells.Among them,heterocyclic derived dyes have been used in disperse dye chemistry for many years due to their excellent brightness of shade.In this dissertation,six parts based on synthesis,structure-performance relationship,dyeing performance,spectral properties and metal-complexion are reported.Corresponding results are showing as follows:1.Six azo dyes derived from the common 2-amino-4-chloro-5-formylthiophene-3-carbonitrile unit and different aniline based couplers were synthesized by the traditional diazotization-coupling strategy.Solvatochromism has been studied for this family of donor-?-acceptor heterocyclic azo dyes.Furthermore,UV-Vis spectral comparisons?maximum absorption wavelength,molar extinction coefficient and full width at half maximum?have been made between the six new azo dyes reported in this work and four previously reported 4-nitro-4'-amino-azobenzene disperse dyes.In addition,X-ray single-crystal structure of one representative azo dye has been included,which constitutes the first structural report on azo dyes containing the 2-amino-4-chloro-5-formylthiophene-3-carbonitrile diazo component.2.A series of full heterocyclic hydrazone dyes has been synthesized by classic diazotization reactions between 2-amino-3-cyano-4-chloro-5-formylthiophene and five pyridine-2,6-dione based coupling components,including two products undergoing dimethylacetalization of aldehyde group of 1 moiety in the presence of methanol and glacial acetic acid.¹H NMR spectral and single-crystal X-ray diffraction studies reveal the presence of hydrazone form for this family of dyes both in solution and in the solid state.Solvatochromism and acid-base discoloration have been studied by means of UV-Vis spectra.More interesting,fabric discoloration has been firstly observed for this family of dyes on five representative fibers?Polyester,Nylon,Silk,Wool and Cotton?under different pH values.It is believed that azo-hydrazone tautomerism of this family of dyes is responsible for the above-mentioned solvatochromism,acid-base and fabric discoloration.3.A series of S-containing heterocycle based pyrazolone dyes were successfully synthesized by traditional diazotization reaction.The azo-hydrazone tautomerism of an representative dye has been achieved by pH titration and evidenced by UV-Vis spectrum.Solvatochromism has also been studied by UV-Vis spectrum using four organic solvents?DMF,CH₃OH,CHCl₃ and CH₂CI₂?each with different solvent polarity index.The structural report of an pyrazolone based dye,4-chloro-5-?dimethoxymethyl?-2-?2-?2-methyl-4-oxo-5-phenyl-pyrrol-3-ylidene?h ydrazinyl?thiophene-3-carbonitrile,is also presented.To date,there have been only four structural reports on pyrazolone based dyes.4.Three new N-acylamino-pyridine-2,6-dione compounds have been synthesized and they are firstly used as the coupling components to prepare corresponding heterocyclic dyes.These dyes exhibit the same hydrazone-tautomeric form,which could be verified by X-ray single-crystal structures and ¹H NMR spectra.Reversible acid-base discoloration has been studied by the pH titration experiments,which could be ascribed to the interconversion between hydrazone and deprotonated azo forms evidenced by an isoabsorptive point in the UV-Vis spectra.Comparisons on their dyeing performance have been made with five commercially available pyridine-2,6-dione based disperse yellow dyes.In order to evaluate their stability,oxidation of these dyes under the basic condition is further explored and three ring-degradation?ring-opening and subsequent oxidative cleavage?products are yielded.Our results reveal the relatively poor basic stability for pyridine-2,6-dione based dyes under the oxidized condition should be avoided in the dyeing and post-treatment processes.5.A pair of isomeric triazene H₂L and azo dye D₁ was synthesized successfully under different pH values through the reaction between 2-amino-3-cyano-4-chloro-5-formylthiophene and 2-amino-5-nitrophenol.Two Cu???complexes of H₂L formulated as {[Cu?L'??H₂O?₂]DMF}n?C1?and[Cu₂L₂?DMF?₂]?C2?were obtained by means of the conventional coordination reactions between triazene ligand H₂L and different copper salts?CuCl2�2H₂O and Cu?OAc?2�H₂O?at room temperature.A new in situ formed ligand L'^2-was obtained by Cu???mediated phenyl halogenation of L^2-during the formation of C1 in a high yield of 78%,which has been evidenced by the X-ray single-crystal structure.A control experiment by using Cu?OAc?₂�H₂O as a metal source reveals the formation of a dinuclear Cu???complex C2 with the expected L^2-ligand.We believe this presents a new approach to achieve the aromatic halogenation under a mild experimental condition with a high yield.6.A dinuclear Cu???complex[Cu₂?L₃?₂]�2H₂O,having an unprecedented in situ formed diphenolate 2,6-piperidin-4-one derived ligand produced from the flexible Schiff-base ligand HL₁,can be yielded as a side product in the presence of Cu?OAc?₂�H₂O/NH₃-H₂O dissolved in methanol and acetone,besides the expected dinuclear Cu???complex[Cu₂?L₁?₄].