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This paper aims to present the design and synthesis of a series of novel antibacterial monoazo disperse dyes based on sulfonamide derivatives to combine the dyeing and functional finishing steps on polyester into one process.

The diazoniom salts of sulfonamides, namely, 4-amino-N-(2-pyrimidinyl) benzenesulfonamide, 4-amino-N-(4-methyl-2-pyrimidinyl) benzenesulfonamide and 4-amino-N-(4,6-dimethyl-2-pyrimidinyl) benzenesulfonamide were prepared and then coupled to N,N-diethyl aniline, N,N-dicyanoethyl aniline and N,N-dihydroxy ethyl aniline, respectively, to produce the dyes.

The structures of the dyes were characterized using their spectral data (FTIR, 1H-NMR, UV-Vis) and elemental analysis. The results indicated that all the dyes exhibit positive solvatochromism in more polar solvents. Dispersion of the dyes was prepared in water and applied to polyester fabrics. The synthesized dye 3a which had good exhaustion on the fabric (89.98 per cent) and were tinctorially stronger (28899 l/mol.cm) showed higher visual colour yield (16.51). The antibacterial efficacy of the dyes was assessed, and they showed activity against both gram-positive and gram-negative bacteria but in different levels depending on their structures.

A simple way to combing functional finishing and dyeing in one process was successfully performed via design and synthesis of disperse dyes with an antibacterial moiety incorporated into dye molecules. The dyes were fully charaterized and evaluated on polyester.

A series of novel antibacterial monoazo disperse dyes based on sulfonamide derivatives were synthesized. The authors studied their application for dyeing of polyester fabric. The dyes offered good results in terms of preparation, yield, purity, visual colour yield, fastness properties and activity against bacteria.

The purpose of this study aims to synthesize a novel donor–acceptor dye based on phenothiazine as a donor (D) and nonconjugated spacer was devised and synthesized by condensing of 2,2'-(1H-indene-1,3(2H)-diylidene) dimalononitrile with aldehyde and the practical synthesis methodology as given in Scheme 1.

The prepared phenothiazine dye was systematically experimentally and theoretically examined and characterized using nuclear magnetic resonance spectroscopy (1H,13C NMR), Fourier-transform infrared spectroscopy (IR) and high-resolution mass spectrometry. Density functional theory (DFT) and time-dependent density functional theory DT-DFT calculations were implemented to determine the electronic properties of the new dye

The UV-Vis absorption and fluorescence spectroscopy of the synthesized dye was investigated in a variety of solvents with varying polarities to demonstrate positive solvatochromism correlated with intramolecular charge transfer (ICT). The probe’s quantum yields (Фf) are experimentally measured in ethanol, and the Stokes shifts are found to be in the 4846–9430 cm⁻¹ range.

The findings depicted that the novel (D-π-A) chromophores may act as a significant factor in the organic optoelectronics.

This paper aims to prepare a new donor–π–acceptor (D–π–A) and acceptor–π– D–π–A (A–π–D–π–A) phenothiazine (PTZ) in conjugation with vinyl isophorone (PTZ-1 and PTZ-2) were designed and their molecular shape, electrical structures and characteristics have been explored using the density functional theory (DFT). The results satisfactorily explain that the higher conjugative effect resulted in a smaller high occupied molecular orbital–lowest unoccupied molecular orbital gap (Eg). Both compounds show intramolecular charge transfer (ICT) transitions in the ultraviolet (UV)–visible range, with a bathochromic shift and higher absorption oscillator strength, as determined by DFT calculations.

The produced PTZ-1 and PTZ-2 sensors were characterized using various spectroscopic methods, including Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy (¹H/¹³CNMR). UV–visible absorbance spectra of the generated D–π–A PTZ-1 and A–π–D–π–A PTZ-2 dyes were explored in different solvents of changeable polarities to illustrate positive solvatochromism correlated to intramolecular charge transfer.

The emission spectra of PTZ-1 and PTZ-2 showed strong solvent-dependent band intensity and wavelength. Stokes shifts were monitored to increase with the increase of the solvent polarity up to 4122 cm⁻¹ for the most polar solvent. Linear energy-solvation relationship was applied to inspect solvent-dependent Stokes shifting. Quantum yield (ф) of PTZ-1 and PTZ-2 was also explored. The maximum UV–visible absorbance wavelengths were detected at 417 and 419 nm, whereas the fluorescence intensity was monitored at 586 and 588 nm.

The PTZ-1 and PTZ-2 dyes leading to colorimetric and emission spectral changes together with a color shift from yellow to red.

The purpose of this paper is to investigate some novel bis‐hetaryl dyes containing both azo and azo methine chromophores on their molecular structures: two series of different molecular structures of these dyes were synthesised. The spectral characteristics and the relationships between colour and constitution of these dyes in solvents with different polarities were systematically investigated and discussed.

A series of novel bichromophoric dyes containing azo and azomethine chromophores were synthesized using two kinds of reaction routes. 2‐amino‐4‐(p‐substituted) phenyl‐thiazole derivatives, which are coupling components, were subjected to diazotisation with aniline derivatives and then to condensation with benzaldehyde derivatives. By exchanging the synthesis route, two series of bichromophoric dyes could be obtained.

The maximum absorption wavelengths of the obtained dyes would be attributed to the higher bathochromic shift in basic organic solvent with high polarity, such as dimethylformamide, as compared with the solvent with low polarity, such as chloroform.

In the present study, a series of novel bichromophoric dyes were synthesized by means of two‐step pathway. In addition, the effects of substituent on the primary aromatic amine and on benzaldehyde moieties will also be discussed.

This novel synthesis method of the thiazole ring would lead to the formation of 2‐amino‐4‐(p‐substituted)phenyl‐thiazole with heteroaromatic coupling component position at C‐5, and consequently would produce the heteroaromatic diazo component at C‐2 for the preparation of the heteroaryl diazo dyes.

In this paper, the bichromophoric dyes obtained by different synthesis routes would indicate that the effect of solvent polarity should be responsible for the bathochromic shifts of the dyes.

To evaluate the photo, thermo, piezo and solvatochromism of new bis‐imidazole derived from three isomers of chlorobenzaldehyde.

The synthesis of the three new bis‐imidazoles was accomplished using modified procedure of the previously reported method, by dissolving the imidazol derivative and cooling in ice bath, and adding potassium ferricyanide drop wise. The compounds were used evaluate the effects of the position of the substitutions on the aromatic ring, on the photo, thermo and piezochromic properties.

New bis‐imidazole derived from 2‐chloro, 3‐chloro and 4‐chloro phenyl have been synthesised and their photochromic properties upon irradiation with ultraviolet light were studies in different solvents. The photochromic properties and performance were affected remarkably upon changing the solvent. Also, the thermochromic properties upon heating in different solvents were studied. The dimers showed piezochromism on grinding.

The method reported for the synthesis is simple. The new compounds showed photochromic, thermochromic, piezochromic, and solvatochromic making them potential candidates for many applications such as sensors, optical data storage and heat sensitive materials.

The method for preparation was modified and improved. The materials prepared were new compounds.

The purpose of this study, 3-aminopyridine, 8-aminoquinoline and some new synthesized 2-aminobenzothiazoles were diazotized with nitrosyl sulfuric acid and subsequently coupled with 5-chloro-8-hydroxy quinoline to synthesize the corresponding heteroarylazo dyes 6–13.

The structures of dyes were characterized by mass, Fourier transform infra red, ¹H proton nuclear magnetic resonance and ultra violet-visible spectroscopic techniques. Absorption spectra of the dyes were measured in acetic acid, ethanol, chloroform, acetonitrile, dimethyl formamide and dimethyl sulfoxide and correlated with the nature of the solvents and substituents. The effects of varying pH on the absorption wavelengths of the azo dyes were also studied. In addition, the acidity constants (pKa) of the dyes were determined using the spectrophotometric method in an ethanol-water mixture (80:20, v/v) at 20–23°C. Besides, density functional theory (DFT) calculations were carried out to compare the energies of proposed azo and hydrazone tautomers of the dyes.

The results showed that the withdrawing chloro groups on the diazo moiety have significant influence (red shift) on the electron absorption spectra of these dyes. In addition, introducing electron withdrawing chloro groups into the benzothiazoles moiety increased the acidic character of dyes.

The synthesized 7-hetroarylazo-5-chloro-8-hydroxy quinoline dyes are new members in the 8-hydroxyquinoline azo dyes family, where very few details regarding the synthesis of such dyes are reported before in the literature. They are unique in terms of synthesis, spectral properties and DFT calculations.

This paper aims to synthesize new benzimidazole dyes aiming to study the solvent effects on their absorption in Ultraviolet-visible spectra.

Ureido/thioureido hydrazonamide benzimidazoles (U/THB) are prepared by condensation of N-aryl-1H-benzo[d]imidazole-2-carbohydrazonoyl bromides with ureido and/ or thioureido reagents. The target products are fully characterized for structural elucidation by means of their spectral and elemental methods. Solvatochromic behavior of U/THB dyes has been studied in different polar protic solvents at room temperature.

The absorption spectra distinguish two main bands at (350 nm–442 nm) and (308 nm–382 nm) referring to n-π* and π- π* transitions of the azo groups. Dimethyl formamide induces an extremely bathochromic transition comparing to the other protic solvents. The observed bathochromic shifts indicate strong interaction with solvents in the excited state. Most dyes show one absorbance in all solvents used, so they may exist in a single tautomeric form (hydrazo form).

In the present paper, the synthesis of U/THB dyes was achieved by a simple and convenient pathway. In addition, the variations in substituents attached to the chromophoric moiety could also be studied.

The new U/THB dyes are accountable for providing good knowledge about their solvation and spectral properties of an order acceptable for industrial utilization.

Synthesis of these new benzimidazole derivatives and study of their solvation and spectral properties provides good knowledge, which is very useful in many industrial applications (e.g. dye-sensitized solar cell, etc.).

The synthesized mono azo U/THB dyes are novel members in the benzimidazole family, where no details regarding the synthesis of such dyes are reported before in the literature. They are superior in terms of preparation, multiple applications and spectral properties.

This paper aims to synthesize 6-ethyl-4-hydroxyquinolin-2(1H)-one as a new enol-type coupling component in the preparation of some 3-arylazo-4-hydroxyquinolin-2(1H)-one dyes and evaluate the solvent effects on their absorption in ultraviolet-visible spectra.

6-Ethyl-4-hydroxyquinolin-2(1H)-one was synthesized by thermal cyclocondensation reaction of N, N′-bis(4-ethylphenyl) malonamide at 130–140°C in polyphosphoric acid. This compound was then applied in the azo-coupling reaction with some aniline-based diazonium salts, so as to prepare seven new mono-heterocyclic azo dyes. The structures of the compounds were confirmed using mass spectroscopic technique. Fourier transform infra red (FT-IR) and 1H proton nuclear magnetic resonance (1H NMR) and carbon-13 nuclear magnetic resonance (13 C NMR) studies on the structure of the azo compounds revealed that they exist as two E- and Z-isomers of hydrazone tautomer both in solid and solution state. The effects of acid and base on the visible absorption spectra of the dyes were also evaluated and discussed.

Ultra violet-visible UV-vis absorption spectra of the dyes didn’t show significant variation by changing of solvents because of intramolecular H-bonding between proposed hydrazone forms and 2- and 4-keto functions in their structures. The spectra of the dyes were not sensitive to the addition of acid but were very sensitive to base.

The synthesized 3-arylazo-4-hydroxyquinolin-2(1H)-one dyes are new members in the 4-hydroxyquinolin-2(1H)-one azo dyes family, where very few details regarding the synthesis of such dyes are reported before in the literature. They are unique in terms of synthesis and spectral properties.

The purpose of this paper is to test absorption characteristics of some newly synthesised 4‐hidroxycoumarins, containing phenyl‐prop‐2‐enoyl group at the 3‐position. Change in spectral characteristics in solvents of different polarity (chloroform and acetonitrile) was followed in regard to the influence of the substitution at the phenyl ring and influence of concentration H⁺ ions. Effectiveness of tested substances was compared with well‐known UV absorbers such as benzophenone‐3 and butyl methoxydibenzoylmethane (BMDM).

All the tested substances were dissolved in chloroform and acetonitrile, with 10‐3 mmol concentration range. The pH was adjusted using 0.1 mol/l HCl, glacial acetic acid, 0.1 mol/l NaOH (aqueous solution) and 0.1 mol/l NaOH (methanolic solution). Spectrophotometric measurement was recorded in the range of 200‐800 nm, using 1‐cm quartz cells.

The tested 4‐hydroxycoumarin derivatives showed good UV absorption properties in the range 280‐380 nm. Substitution on the phenyl ring changes the shape of the absorption maxima. The changes depend on the properties of the substituent as well as the acidity of the solution.

Introducing an electron‐donating substituent on the phenyl‐prop‐2‐enoyl group can shift absorption maximums to longer wavelength. In addition, the variation in substituents on the synthesised substances and pH of the solution could also be studied.

The new compounds showed good UV absorption, making them potential candidates for many applications. The practical importance of the tested substances are derived from their stability, relatively easy synthesis and good UV absorption properties.

The paper shows that the tested coumarins derivatives were new compounds with good UV absorption properties, making them good UV absorbers of commercial potential. The tested coumarins showed good UV absorption properties in the range 280‐380 nm, making them potential candidates for many applications.

The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices.

The poly(methyl methacrylate) PMMA and epoxy resin doped with photochromic spirooxazine (SO) are prepared and the effects of ultraviolet (UV) irradiation are studied using spectrophotometer. The reversible reaction is effected using white light. Photochemical fatigue resistance of these films is also studied.

Irradiation of colourless 7′,8′‐dichloro‐1,3,3‐trimethylspiro[indoline‐2,3′‐[3H]benzo[b][1,4]oxazine] (SO) doped in PMMA and epoxy resin with UV light (366 nm) results in the formation of an intense purple‐red coloured zwitterionic photomerocyanine (PMC). The reverse reaction is photochemically induced by irradiation with white light. Photocolouration and photobleaching reactions follow a first‐order rate equation. It is found that photocoloration rate constant of (SO) in both matrices is almost the same, which is unexpected. On the other hand, the rate of photobleaching reaction of (PMC) in PMMA is twice slower than that in the epoxy resin. It seems that the presence of the two chlorine atoms at positions 7′ and 8′ of the benzooxazine moiety destabilise the PMC in epoxy resin film and results in speeding up the fading process compared to that in PMMA. SO doped in epoxy resin shows much better fatigue resistance than that doped in PMMA.

The PMMA and epoxy resin polymers doped photochromic spirobenzooxazine described in this paper were prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds.

The photochromic materials developed can be used for different applications, such as coatings and holography.

The method developed may be used to enhance the performance of photochromic materials.