Papers by Keyword: Chromophore

Abstract: Procion M dyes are widely used reactive dyes for cellulose-based textiles due to their bright colors, fastness properties, and covalent bonding capabilities. This study examines the chemical structure of Procion M dyes, highlighting key components: the chromophore, reactive group, solubilizing group, and linking group. The hydrolysis and alcoholysis of these dyes were investigated using Procion Red M-X5B and Procion Blue M-XG under various temperatures (25°C, 35°C, 45°C). Experimental setups included UV-Vis and IR spectroscopy to monitor dye concentration and functional group changes, respectively. Data revealed temperature-dependent reaction rates, with higher temperatures accelerating both hydrolysis and alcoholysis. Thermodynamic analysis showed that both processes are exothermic and spontaneous, with enthalpy changes of -20 kJ/mol (hydrolysis) and -25 kJ/mol (alcoholysis), and Gibbs free energy changes confirming spontaneity. FTIR and HPLC analyses provided insights into molecular structural changes and product formation. These results underscore the efficiency and temperature sensitivity of Procion M dye reactions, offering valuable information for optimizing textile dyeing processes.

Abstract: The synthesis of a suite of compounds containing three chromophores coupled to a central nitrogen atom are reported. X-ray crystallographic data has been obtained for two of the compounds and this suggests that incorporation of these molecules into such a trichomophore bundle is a valid strategy for minimizing dipole-dipole interactions, and therefore aggregation in these compounds.

Abstract: How to used non-EU-banned insoluble azo dyes to prepare a new-type colour-display anti-counterfeiting paper(ACP) is investigated in this paper. The ACP will display red spots when it is wiped with alcohol. Through studying its mainly affecting facts ,including the dosage of Naphthol AS-BO ,dosage of Chromophore Red-B, the Chromophore's pH value and the drying temperature etc.,the best optimize technological conditions are obtained of insoluble azo dyes' color-displaying on the paper for the purpose of anti-counterfeiting. After the red spot are displayed in the paper,the chromatic aberration and physical properties of the paper are detected. The results showed that the paper made by adding Chromophore Red-B and Naphthol AS-BO had a very good anti-counterfeiting effect, while its physical properties had only changed a little.

Abstract: A novel calix[4]arene chromophore 1 was synthesized by introduction of two D-π-A units (4-nitrophenyl)azophenyloxy groups) on the lower rim of calix[4]arene. The measurement results of hyper-Rayleigh scattering (HRS) and UV-vis spectra show that the static first molecular hyperpolarizability of the chromophore 1 is more than two times that of the corresponding mono-D-π-A unit reference compound 4-(4-nitrophenylazo)phenol 2, without causing red-shift of absorption band.

Abstract: We have investigated the optical absorption and photoluminescence (PL) of a classical banana-shaped liquid crystal, 1,3-phenylene-bis[4-(4'-nonyloxy)phenyliminomethyl]benzoate, in dilute solutions of tetrahydrofuran. Upon the 325 nm excitation from a helium-cadmium laser, the dilute tetrahydrofuran solutions of the banana-shaped compound gives off strong PL with its peak located at about 380 nm (3.26 eV). Interestingly the PL spectrum of the banana-shaped compound has a long tail that extends beyond 500 nm. In order to explore the origin of the PL, we have calculated the electronic structures of the three chromophores in the banana-shaped compound: the central benzene ring (chromophore A), the carbonyl linkage (chromophore B), and the Schiff base bridged two benzene rings in the branched arms of the molecule (chromophore C). Our results have shown that chromophore C is responsible for the 380 nm PL band where the chromophore B is responsible for the long tail in the recorded PL.

Abstract: synthesis and characterization of a new chromium- calcium titanate red ceramic pigment is described in this communication. The pigment is based on the solid solution of chromium (IV) in calcium titanate and was characterized as red-brown pigment in a CaO-ZnO-SiO2 transparent glaze used for ceramic tiles (1080°C). XRD, UV-Vis-NIR spectroscopy and CIE-L*a*b* techniques of characterization have been employed. The L*a*b* valour of the optimal pigment with 0,015 mol/mol of chromium fired at 1100°C with a soaking time of 3 hours and 5% weight added to the transparent glaze is 59.3/12.5/9.5. Likewise 5%w. addition of NHCl used as flux agent increase b* and decrease L* valour (L*a*b*=45.2/15.3/5.3).

Abstract: Research on new ceramic dyes is addressed to obtain best pigmenting materials in order to reach higher thermal stability (e.g. for porcelainised stoneware) than classical pigments, higher chemical stability towards the coloured matrix or low toxicity in order to satisfy health and environmental requirements. The earlier developments on the research in new ceramic pigments based on new crystal structures (e.g. perovskite, hexaaluminates, fergusonite, pseudobrookite …), new chromophores (e.g. ruthenium, bismuth and rare earth ions), or new methods of preparation are discussed in this communication.

Abstract: A new series of oligothienyl-imidazo-phenanthrolines 3 were synthesised in good to excellent yields by condensation of 5,6-phenantroline-dione 2 with formyl-thiophene derivatives 1 in the presence of ammonium acetate in glacial acetic acid. Furthermore, their solvatochromism and molecular optical nonlinearities were determined and comparatively studied. The experimental results indicate that phenanthrolines 3, due to their moderate solvatochromic properties and good optical nonlinearities, could be used as suitable probes for the determination of solvent polarity and as nonlinear optical materials.