Jolanta Sokolowska-Gajda

Synthetic dyes based on environmental considerations. Part 2: Iron complexes formazan dyes☆

Abstract This paper is concerned with the synthesis and evaluation of some 1:2 iron complexed formazan dyes for use on wool and nylon. The chemical structures of these new dyes were confirmed with the aid of negative ion FAB mass spectrometry, a technique which also proved instrumental in establishing the nature of the products obtained when unsymmetrical 1:2 iron complexed formazan dyes were synthetic targets. It is clear from the fastness properties obtained that certain of the title compounds could have utility in applications requiring high hightfastness.

Synthetic Dyes Based on Environmental Considerations Part I: Iron Complexes for Protein and Polyamide Fibers

We have described the synthesis of some novel 1:2 Fe complexed azo dyes and compared their properties with 1:2 Cr and 1:2 Co commercial analogs. We also report the interesting FAB mass spectroscopy analysis of 1:2 metallized azo dyes resulting in the formation of 1:1 complexed dyes and their unmetallized precursors. Results from light- and rubbing-fastness evaluations of these 1:2 Fe metallized dyes show the black dyes to be strong candidates for use on wool and nylon in applications requiring high lightfastness.

Photochemical degradation of some aminoazobenzene and related 3-amino-5-nitro(2,1)benzisothiazole-based dyes in ethanolic solution

Abstract This paper reports some kinetic measurements of the photofading in ethanol of some aminoazobenzene and related 3-amino-5-nitro(2,1)benzisothiazole-based disperse dyes derived from, as coupling components, derivatives of N-benzyl N-phenyl-β-alanine with different substituents in the benzyl or phenyl residue. A fair linear relationship between the measured fading rate and σ o constants of ortho substituents in the phenyl ring was found. The influence of substituents in the benzyl group on the rate of fading was not noticeable.

A new medium for the diazotization of 2-amino-6-nitrobenzothiazole and 2-aminobenzothiazole

Abstract To identify a useful alternative to H 3 PO 4 as a medium for diazotizing heteroaromatic amines a number of organic acids having a similar ionization constant (K 1 ) were examined. It was found that dichloroacetic acid is an effective solvent for both the diazotization of the title compounds and the synthesis of important commercial disperse dyes based on these amines. Dyes such as C.I. Disperse Red 177 and Disperse Violet 52 were readily obtained in 85–90% yield and very pure form.

The synthesis of disperse and cationic dyes from acid dye structures

Abstract This paper is concerned with the conversion of some mono- and di-sulfonated naphthol azo dyes to disperse dyes suitable for poly(ethyleneterephthalate) fibers, and cationic dyes for cationic dyeable polyester and acrylic fibers. The chemical structure of these new dyes has been confirmed by 1 H-NMR, FAB or DCI mass spectrometry, and in some cases by elemental analysis. Some fastness properties and absorption spectral data of both types of dyes are also reported, as well as an interesting limitation in the naphthalene-based acid dyes suitable for the described conversion.

Field desorption mass spectral analysis of some nonmutagenic benzidine-based pigments

Abstract This paper is concerned with field desorption mass spectral (FDMS) analysis of novel disazomethine, disazoacetoacetanilide (diarylide) and disazopyrazolone pigments containing nonmutagenic benzidine homologs. The FD spectra of the aforementioned types of pigments are characterized by intense parent ion peaks [M +. ] and relatively intense [M + ]/2 daughter ions, a pattern which serves as a fingerprint for these molecular structures.

The Application of Some Alkyl Esters of Alkoxy Derivatives of N-Benzyl-N-phenyl-β-alanine in the Synthesis of 3-Amino-5-nitro[2,1]benzisothiazole-Based Dyes

Abstract This paper is concerned with the application of alkoxy derivatives of some alkyl esters of N-benzyl-N-phenyl-β-alanine in the synthesis of heterocyclic azo dyes derived from 3-amino-5-nitro [2,1] benzisothiazole. The structure of the alkoxy intermediates was confirmed by IR and 1 H-NMR. The dyes were evaluated on polyester-fibre fabric with respect to their basic fastness properties. IR, 1 H-NMR, and visible spectra of the dyes were also examined.

Photodegradation of CI Acid Orange 60 and CI Acid Green 25 in an Amide Environment

Photodegradation, in solution and in nylon 66 fiber, of two automotive acid dyes (CI acid orange 60 and CI acid green 25) for nylon carpet has been investigated. Photofading in solution was done in dimethylformamide (DMF) with the aid of a 254-nm light source, and the work in nylon fiber used the xenon arc light of an Atlas CI 65 weatherometer. The results show that these dyes fade via a photoreduction process under both sets of conditions, and they suggest that DMF is a suitable model for nylon in characterizing the photodegradation of acid dyes. The structures of the degradation products of the two dyes were determined with the aid of fast atom bom bardment and desorption chemical ionization mass spectrometry and by HPLC and TLC comparisons with authentic samples.

Photodegradation of some 1:2 metal complexed azo dyes in an amide environment

The photodegradation of some metallized azo dyes was investigated. The photofading was done in DMF using 300 nm, 350 nm and daylight irradiation. The quantum yield Φ of the photodegradation performed under UV light was measured and it was found that the metal present in the molecule of dye and the photolysis wavelength influence this process significantly. The presence of a ketone sensitizer like benzophenone accelerates the photofading of dyes, confirming that hydrogen abstraction is responsible for their degradation. It was observed that oxygen plays a very important role in the photolytic behaviour of the studied dyes under daylight exposure. Co(III) complexed azo dyes, contrary to Cr(III) and Fe(III) analogues, were found to be effective singlet oxygen quenchers. Additionally, the expected relationship between log Φ and the reciprocal of lightfastness was found.

The photofading of some aminoazobenzene dyes on polyester

Abstract A study of the photofading of some aminoazobenzene disperse dyes derived from N-benzyl N-phenyl-β-alanine on polyester fabric was carried out. A reasonable linear relationship between the fading rate, measured on the basis of the change of colour parameters (P%, L) as a function of irradiation time, and σ 0 constants of ortho substituents in the phenyl ring of the coupling components was found.