Ethyl 2-amino-4-phenyl-4H-1-benzo­thieno[3,2-b]pyran-3-carboxyl­ate

The title heterocyclic compound, C20H17NO3S, was synthesized by condensation of ethyl cyano­acetate with (Z)-2-benzyl­idenebenzo[b]thio­phen-3(2H)-one in the presence of a basic catalyst in ethanol. The phenyl and ester groups make dihedral angles of 77.67 (6) and 8.52 (6)°, respectively, with the benzothienopyran ring system [maximum r.m.s. deviation = 0.1177 (13) Å]. In the crystal, centrosymmetric dimers are formed through pairs of N—H⋯O hydrogen bonds between the amine and ester groups. Inter­molecular C—H⋯N hydrogen bonds and C—H⋯π inter­actions involving the thio­phene ring are also observed

Investigation of inks, pigments and paper in four Moroccan illuminated manuscripts dated to the eighteenth century

UID/FIS/04559/2020 VICARTE UIDB/00729/2020The heritage left by the Arab world in the history of science is directly related to the innovations in both the manufacturing of paper and the production of ink. Four Moroccan manuscripts dating to the eighteenth century, conserved at the royal library of Rabat, have been analyzed by X-ray diffraction (XRD), energy-dispersive X-ray fluorescence spectrometry (EDXRF), scanning electron microscopy coupled to energy dispersive X-ray spectroscopy (SEM–EDS), Raman and attenuated total reflection Fourier transformed infrared spectroscopy (FTIR-ATR). The combination of the Raman, EDS, and EDXRF spectroscopies results allows us to Characterized the inorganic inks, pigments and fillers used in paper making process. Iron-based ink was used for writing the text for all manuscripts. The main pigments used in the titles and in the illuminated part are found to be vermillion and red ochre in red samples, azurite with barium white and ultramarine in blue color, lead chromate in yellow color, copper and arsenic based ink in green color, carbon black for black color and gold. The main fillers identified in paper are calcite and kaolin. FTIR-ATR and Raman analysis revealed the presence of the characteristic bands of cellulose, the main component of paper. XRD confirms the presence of the fillers detected by FTIR-ATR. Finally, SEM allows to have a better knowledge of the typical morphology of the paper highlighting some effects of the degradation process. Graphic abstract: [Figure not available: see fulltext.]publishersversionpublishe

(2RS,4′RS)-3′-(3-Chloro-4-meth­oxy­phen­yl)-4′-phenyl-4′H-spiro­[indene-2,5′-isoxazol]-1(3H)-one ethanol monosolvate

The title compound, C23H17ClN2O3·C2H6O, is the stoichiometric 1:1 ethanol solvate of a racemic reaction product, which forms a conglomerate. The refined Flack parameter of 0.36 (3) indicates racemic twinning. In the structure, mol­ecules are linked into zigzag chains by a series of inter­molecular N—H⋯O and O—H⋯O hydrogen bonds

3′-(4-Meth­oxy­phen­yl)-4′-phenyl-3H,4′H-spiro­[1-benzothio­phene-2,5′-isoxazol]-3-one

In the title compound, C23H17NO3S, the thio­phene and isoxazole rings each have an envelope conformation with the spiro C atom linking them forming the flap of the envelope in each case. The dihedral angle between the mean planes of the benzothio­phene ring and isoxazole rings is 81.35 (7)°. In the crystal, an inter­molecular C—H⋯O hydrogen bond links the mol­ecules into a chain running parallel to the a axis

Homogeneous Esterification of Cellulose in the Mixture N-Butylpyridinium Chloride/Dimethylsulfoxide

The present study deals with the homogeneous acylation of cellulose with p-nitrobenzoyl chloride in a reaction medium composed of a mixture of 1-butylpyridinium chloride and dimethylsulfoxide (BPyCl/DMSO), in the presence of different bases and under mild conditions. The preparation of cellulose p-nitrobenzoate depending on the reaction conditions, the influences of reaction parameters such as the base type, and the types of cellulose (kraft and microcrystalline) on the products were investigated. Cellulose p-nitrobenzoate with a degree of substitution (DS) in the range from 0.12 to 1.5 was accessible, with a low excess of reagent and for a short reaction time. The cellulose esters were characterized by 1H-NMR, 13C NMR, and FT-IR spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and solubility tests

Antibacterial Properties of Functional Polyamide 6.6

Polyamide 6.6 multifilaments are grafted with the monomer N-allyliminodiacetic acid for the purpose of removal of some heavy metal ions from their aqueous solutions by forming its metal chelate especially with Ag+ ion. Such a fibrous chelate-forming resin has been used with success due to its large surface area, which contains an important metal chelate-forming functional group, where metal ions are adsorbed or desorbed on its surface, and therefore having an improved adsorption and desorption capability. In previous work, chelate-forming fibre was characterised by ICP-AES analysis according to the digestion method by microwave. The antibacterial activity of the prepared fibre is investigated with Escherichia coli bacteria as reference, according to the zone of inhibition method in agar medium. The material used as reference without metal does not present any effect on E. coli. However, the chelateforming fibres with Ag+ have a strong bactericidal effect, even with a low concentration of silver ions. These modified materials can be used as highly effective bactericidal composites that may be used in future applications for the production of antimicrobial textiles, papers or polymer material

Strong Modulation of Two-Photon Excited Fluorescence of Quadripolar Dyes by (De)Protonation

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Luminescent hybrid coatings prepared by a sol–gel process for a textile-based pH sensor

International audienceFluorene- and stilbene-based fluorophores were synthesized and characterized by NMR, IR, and mass spectroscopy (ESI-MS). These fluorescent dyes were coated onto cotton fabrics by the sol–gel method using tetraethylorthosilicate (TEOS) and propyltriethoxysilane (PTES) as silica precursors. Herein, the optical properties of the synthesized compounds and the elaborated fabrics were studied. The luminescent properties of the fluorophores were examined in three forms: as a powder, dissolved in ethanol, and grafted onto the fabric by the sol–gel method. Furthermore, the effect of the fluorophore concentrations in the sol–gel solution on the fluorescence properties of the elaborated hybrid coatings was investigated. The synthesized fluorophores exhibited good pH sensitivity and a strong wavelength shift in acidic or basic media, ascribed to the protonation–deprotonation of the phenolic groups and pyridine of the fluorophore molecules. Alongside this, we successfully developed pH-sensitive fluorescent textiles and tested their efficiency in different pH media