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Novel 1H‐pyrazole analogues were generated in high yields via the cyclocondensation of chalcone derivatives with p‐toluene sulfonyl hydrazine, utilizing K2CO3 and iodine as catalysts under heat for 2 h. A straightforward and effective manner was carried out for the creation of substituted pyrazoles or triazolopyrimidines via tandem methods containing aryl sulfonyl/benzoyl chloride and 1H‐pyrazole derivatives, or chalcones and 5‐aminotriazole, with catalytic amounts of K2CO3 or KOH, respectively. By researching with different solvents and catalysts, the reaction conditions for this technique were improved, resulting in good to excellent yields of the intended products 4aa‐cb and 6A‐d. This method is observed for its enhanced yields and environmental friendliness. The structures of the novel molecules have been verified by spectroscopic and elemental analysis techniques. The novel targets were validated versus various pathogenic and fungal strains. Contrasting the new series of products to reference drugs, pyrazole derivative 2b were the strongest antimicrobial actions, with MIC values varying from 0.98–19.45 µM. [ABSTRACT FROM AUTHOR]

A sensitive and selective phenothiazine‐based sensor (PTZ) has been successfully synthesized. The sensor PTZ displayed specific identification of CN− 'turn‐off' fluorescence responses with a quick reaction and strong reversibility in an acetonitrile:water (90:10, V/V) solution. The sensor PTZ for detecting CN− exhibits the marked advantages of quenching the fluorescence intensity, fast response time (60 s), and low value of the detection limit. The concentration that is authorized for drinking water by the WHO (1.9 μM) is far higher than the detection limit, which was found to be 9.11 × 10−9. The sensor displays distinct colorimetric and spectrofluorometric detection for CN− anion due to the addition of CN− anion to the electron‐deficient vinyl group of PTZ, which reduces intramolecular charge transfer efficiencies. The 1:2 binding mechanism of PTZ with CN− was validated by fluorescence titration, Job's plot, HRMS, 1H NMR, FTIR analysis, and density functional theory (DFT) investigations, among other methods. Additionally, the PTZ sensor was successfully used to precisely and accurately detect cyanide anions in actual water samples. [ABSTRACT FROM AUTHOR]

A novel phenothiazine derivative conjugated with vinylcyclohexenyl‐malononitrile (PTZ‐CDN) was synthesized through the Knoevenagel reaction of 10‐octyl‐10H‐phenothiazine‐3,7‐dicarbaldehyde with 2‐(3,5,5‐trimethylcyclohex‐2‐en‐1‐ylidene)‐malononitrile and fully characterized. The UV–vis absorption spectra of PTZ‐CDN in different solvents showed a λmax band at 497–531 nm with a high molar extinction coefficient attributed to intramolecular charge transfer (ICT) with the characteristics of a π–π* transition. Increasing the solvent polarity resulted in a bathochromic shift of λmax. The PTZ‐CDN fluorescence emission spectra were more sensitive to increasing the solvent polarity than the absorption spectra; they displayed a blue shift of λem by 85 nm. To understand the behaviour of the PTZ‐CDN derivative, Stokes' shift (Δν¯) with respect to the solvent polarity, Lippert–Mataga and linear solvation–energy relationship (LSER) models were applied in which the LSER showed better regression than the Lippert–Mataga plots (r2 = 0.9627). Finally, the TD‐density functional theory (DFT) electronic transition spectra in dioxane and dimethyl formamide (DMF) were calculated. The DFT data showed that λmax resulted from the support of the highest occupied molecular orbital to the lowest unoccupied molecular orbital transition with 74% and 99% in dioxane and DMF, respectively. [ABSTRACT FROM AUTHOR]

A new typical phenothiazine compound functionalized with thienyl‐indandione derivative (PTZTID) was synthesized and characterized using spectral analysis (ultraviolet–visible (UV–vis) light, infrared (IR), 1H nuclear magnetic resonance (NMR) and 13C NMR tools). The UV–vis absorption spectra of the PTZTID solution in 1,4‐dioxane showed two absorption bands attributed to localized aromatic π–π* transitions of conjugated aromatic moieties and intramolecular charge transfer with the characteristics of a π–π* transition. The fluorescence spectra exhibited a maximum emission wavelength at 580 nm. The effect of concentration on photophysical properties took the form of a minor hypsochromic shift, which was attributed to some extent to the occurrence of H‐type aggregation of the PTZTID derivative. Binary solvent effects on the spectroscopic behaviour of PTZTID were measured at different H2O/1,4‐dioxane ratios. Similarly, when increasing the water content, a hypsochromic shift was observed that resulted from H‐type aggregation. Furthermore, geometry and electronic configurations of PTZTID were studied at density functional theory /B3LYP level and indicated that the compound had a nonplanar (butterfly structure). [ABSTRACT FROM AUTHOR]

This article explains how composite thin films, that are made of both cross‐linked poly(methyl methacrylate) (PMMA) and reinforced with multi‐walled carbon nanotube (CNTs), are designed, fabricated and developed for selective cationic sensing applications. The C‐PMMA‐CNTsa‐e nanocomposites were prepared by in situ cross‐linking reaction technique using 4,4′‐diaminobiphenyl (DABP) as the cross‐linking agent. Variable loading of CNTs varied from 2 to 40 wt% was utilized during the cross‐linking process. The nanocomposite films have been structurally characterized by Fourier transform infrared and XRD and the results confirm the incorporation of CNTs in the C‐PMMA matrix, while the dispersion of CNTs in C‐PMMA was characterized using SEM and TEM. The dispersion of CNTs in the composites was excellent, even at high CNTs loading as indicated by SEM and TEM. TEM images of C‐PMMA‐CNTs nanocomposites reveal a core‐shell structure in which CNTs as the core and C‐PMMA as the shell. The thermal features of the nanocomposite films were investigated through their TGA and DTG data. The results confirmed the importance of CNTs content in enhancing the thermal stability of the nanocomposite. The desired yttrium (Y3+) cation sensor was fabricated using glassy carbon electrode coating with a thin uniform layer of synthesized C‐PMMA‐CNTse nanocomposite. A calibration curve was plotted as current vs. concentration of Y3+ ion. The resulted calibration curve is found linear over linear dynamic range of 0.1 nM–0.1 mM. The slope of calibration curve is used to measure the sensitivity (27.2943 μA μM−1 cm−2), limit of detection (3.48 ± 0.17 pM), and limit of quantification (LOQ; 11.6 ± 0.57 pM) of Y3+ cation. It is also found as reliable sensor to detect Y3+ ion in real environmental samples. Considering the contamination of environment, this research might be reliable way for the development of future prospective cationic sensor for the safety of healthcare and ecological fields. POLYM. COMPOS., 40:E1673–E1684, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Eco‐friendly cross‐linked poly(methyl methacrylate)/multiwall carbon nanotube nanocomposites with general abbreviation (C‐PMMA/CNTs1‐5) have been synthesized and applied efficiently for environmental treatment from methyl green (MG) dye. C‐PMMA/CNTs1‐5 were prepared via in situ cross‐linked polymerization method using 1,12‐diaminododecane as the cross‐linker. CNTs were enforced with variable loading (2, 5, 10, 20 and 40) wt% in situ while the cross‐linking polymerization occurred. The fabricated nanocomposites were spectroscopically regarded by common characterization methods. These include FTIR spectra, XRD diffractograms, SEM & TEM micrographs, and TGA & DTA thermograms. FTIR and XRD showed obvious evidence for the composite formation. A good spreading of CNTs inside C‐PMMA matrix has been investigated by SEM and TEM micrographs. TGA showed enhanced thermal stability behavior in all formulations. Our main target in this study is to test the viability of eliminating MG dye from aqueous solutions by C‐PMMA/CNT nanocomposites. The C‐PMMA/CNT3 nanocomposite showed Langmuir adsorption capacity of 6.85 mmol/g for MG dye at 25°C. The adsorption equilibrium could be reached within 120 min. The adsorption kinetics of MG onto C‐PMMA/CNTs3 was obeyed very well pseudo‐second‐order model. Enthalpy (∆H°) and entropy (∆S°) of adsorption were 23.15 kJ/mol and 134.1 J mol−1 K−1, respectively. The values of ∆H° and ∆G° all designated that the adsorption of MG onto C‐PMMA/CNT3 nanocomposites was a physisorption in nature. [ABSTRACT FROM AUTHOR]

In an effort to provide, assess, and evaluate a theoretical approach which enables designing efficient donor-acceptor dye systems, the electronic structure and optical properties of pyran-squaraine as donor-acceptor dyes used in dye-sensitized solar cells were investigated. Ground state properties have been computed at the B3LYP/6-31+G** level of theory. The long-range corrected density functionals CAM-B3LYP, PBEPBE, PBE1PBE (PBE0), and TPSSH with 6-311++G** were employed to examine absorption properties of the studied dyes. In an extensive comparison between experimental results and ab initio benchmark calculations, the TPSSH functional with 6-311++G** basis set was found to be the most appropriate in describing the electronic properties for the studied pyran and squaraine dyes. Natural transition orbitals (NTO), frontier molecular orbitals (FMO), LUMO, HOMO, and energy gaps, of these dyes, have been analyzed to show their effect on the process of electron injection and dye regeneration. Interaction between HOMO and LUMO of pyran and squaraine dyes was investigated to understand the recombination process and charge-transfer process involving these dyes. Additionally, we performed natural bond orbital (NBO) analysis to investigate the role of charge delocalization and hyperconjugative interactions in the stability of the molecule. [ABSTRACT FROM AUTHOR]

Three phenothiazine-based dyes have been prepared and utilized as dye-sensitized solar cells (DSSCs). The effects of dye-adsorption solvent on the performances of dye-sensitized solar cells based on phenothiazine dyes were investigated in this study. The highest conversion efficiency of 3.78% was obtained using ethanol (EtOH) and 2.53% for tetrahydrofuran (THF), respectively, as dye-adsorption solvents. Cell performance using EtOH as a dye-adsorption solvent showed relatively higher performance than that using THF. Electrochemical and photochemical tests of phenothiazine dyes in solution and adsorbed on the TiO2 surface showed less dye loading and coverage on the TiO2 surface during adsorption in the case of THF, which decreased the solar cell performance of the DSSC using THF as adsorption solvent compared with using EtOH as adsorption solvent. Meanwhile, the steric effect of phenothiazine-based (PT1-3) dyes was also investigated. Dye with longer and branched aliphatic chain in the order of PT1, PT2, and PT3 showed an increased resistance of the recombination reaction and electron lifetime, thereby increasing Voc and enhancing the overall cell performance because of the sterically hindered conformation of the phenothiazines. [ABSTRACT FROM AUTHOR]

Seven reactive dyes judiciously selected based on chemical structures and fixation mechanisms were applied at 2% owf of shade on amidoximated acrylic fabrics. Amidoximated acrylic fabric has been obtained by a viable amidoximation process. The dyeability of these fabrics was evaluated with respect to the dye exhaustion, fixation, and colour strength under different conditions of temperature and dyeing time. Nucleophilic addition type reactive dyes show higher colour data compared to nucleophilic substitution ones. FTIR studies further implicate the binding of reactive dyes on these fabrics. A tentative mechanism is proposed to rationalize the high fixation yield obtained using nucleophilic addition type reactive dyes. Also, the levelling and fastness properties were evaluated for all dyes used. Excellent to good fastness and levelling properties were obtained for all samples irrespective of the dye used. The result of investigation offers a new method for a viable reactive dyeing of amidoximated acrylic fabrics. [ABSTRACT FROM AUTHOR]

Pretreated wool/acrylic fibre was obtained by a facile amidoximation process. Fibre characterisation (nitrogen content, tensile strength, shrinkage, infrared spectra and X-ray diffraction) proved the success of the pretreatment. Union dyeing of wool/acrylic fabrics with acid and reactive dyes, namely CI Acid Red 40, CI Acid Blue 25, CI Reactive Red 194 and CI Reactive Blue 25, was obtained using a one-bath dyeing process. Different factors that may affect the dyeability of the blend fibre, such as dyebath pH, liquor ratio, temperature, time and dye concentration, were evaluated with respect to the dye exhaustion, fixation, colour strength, levelling and fastness properties. Excellent to good fastness was obtained for all samples, irrespective of the dye used. The result of the investigation offers a new viable method for union dyeing of wool/acrylic fibres in a one-dyebath process. [ABSTRACT FROM AUTHOR]

An overview of the recent developments in functional dyes, which are useful for hi-tech applications for those based on optoelectronics, such as dye sensitized solar cells, photochromic dyes and biomedical applications, such as photodynamic therapy for the treatment of cancer and fluorescent sensors is presented. [ABSTRACT FROM AUTHOR]

The article presents information on a study which described the development of an alkaline dyeing of polyester with an alkali-stable disperse dye, Dianix Scarlet AD-RG, using sodium edetate as an alkaline buffering agent. A review of the related literature is presented. It presents the reagents and methods utilized including selected mono and bifunctional reactive dyes. A detailed discussion on the research findings is given.

Urea reduction or elimination in reactive dye print pastes is of ecological interest. Sodium edetate is presented as a complete substitution of urea in the conventional print paste of reactive dyes, namely CI Remazol Black B and Remazol Brilliant Orange 3R using a constant amount of sodium alginate as the thickening agent. Three different print pastes containing urea/NaHCO3, sodium edetate/NaHCO3 and sodium edetate were thoroughly investigated. Different factors that may affect the printability of cotton, such as the concentrations of sodium edetate, urea, dye, absence or presence of alkali and steaming time in the prints obtained were evaluated with respect to the dye fixation, colour strength, dye penetration, levelling and the fastness properties. Excellent to good fastness was obtained for all samples irrespective of the print paste used. [ABSTRACT FROM AUTHOR]

Anionic dyeable acrylic fibre has been obtained by a viable and efficient pretreatment process using hydroxylamine hydrochloride in the presence of acetate salt. The chemical modification relies on an amidoximation reaction that partially converts cyano groups present in the fibre to amidoxime groups. Different factors that may affect the pretreatment process have been investigated. The pretreated fabrics were dyed with CI Acid Red 1 and CI Acid Green 16 and gave improved dyeability over untreated fabrics due to the ion-ion interactions between the sulphonic groups present in the dye molecules and the protonated amino groups present in the fibres. The treated dyed fabrics also showed excellent fastness properties. Fibre characterisation (nitrogen content, tensile strength, shrinkage, infrared spectra and X-ray diffraction) proved the success of the amidoximation reaction. [ABSTRACT FROM AUTHOR]

Reactive cationic agents, phenylmonochlorotriazinyl and epoxypropyl, are used for cotton pretreatment using a pad-dry-curing technique. The dyeability of cationised cotton fabrics using CI Acid Red 1, determined spectrophotometrically for the residual dyebath, has been dependent on the cationic agent concentration and the appropriate mixture used. Comparative sorption isotherms, rate of dyeing at different temperatures, standard affinity, entropy and heat of dyeing for three different pretreated fabrics have been calculated and discussed. The equilibrium data obtained were fitted by the Langmuir isotherm model, allowing the corresponding sorption parameters to be determined. [ABSTRACT FROM AUTHOR]