This work brings syntheses of fulgide derivatives in which 1,4-butanedioic acid is substituted with either arylethylidenes or arylmethylidenes in position 2 and with isopropylidene in position 3. Substitution effects on spectral properties are discussed, too.

Pharmaceuticals diclofenac and naproxen belong to class of non-steroidal anti-inflammatory drugs (NSAIDs). These substances are very often found in outlets of WWTP or in surface waters, because among all classes of pharmaceuticals, they are frequently prescribed and purchased.These substances have by their nature a strong biological effect, so non-target organisms are affected. For example diclofenac causes cytological malformations of liver tissue within a concentration 28 mu g/L (O. mykkis). Sensitive organisms to naproxen are crustaceans, where the EC50 for (C. dubia) is 330 mu g/L, but degradation products of this drug are significantly more toxic. EC50 for degradation products of naproxen to C. dubia are less than 100 mu g/L.Diclofenac and naproxen (500 mu g/L) were from model water samples removed by heterogeneous photocatalysis in 4L batch reactor. After irradiation of the catalyst, the system produces center dot OH radicals, which causes destruction of the organic substance. As the catalyst used was 0.5 g/L titanium dioxide (TiO2, Precheza a.s.). As a source of UV radiation was used UV LED diode Luminus, with peak wavelength at 365 nm. At the same time the effect of hydrogen peroxide (H2O2) or effect of pH was determined. Samples were preconcentrated by solid phase extraction (SPE) and analyzed by high performance liquid chromatography (HPLC). At the same time characteristics and capability of pharmaceutical removal from inlet of WWTP were discussed.

The photocatalytic decomposition of indigo-5,5′-disulfonic acid (indigocarmine) and indigo-6,6′-dicarboxylic acid has been studied using TiO2 suspension and the polychromatic irradiation of a high-pressure Hg arc lamp. The dyestuffs were dissolved in aqueous medium at pH = 10 and photolyzed in a back-flow tubular photoreactor. The reaction products were determined by HPLC, NMR and MS spectroscopy. Two main photoproducts obtained from indigocarmine (2-amino-5-sulfobenzoic acid and isatine-5-sulfonic acid) were detected. The photocatalysis of indigo-6,6′-dicarboxylic acid gave aminoterephthalic acid and isatine-6-carboxylic acid as two main products. The quantitative analyses of reaction products were performed with UV/Vis and HPLC using chemical standards. A stoichiometric model and kinetic description of photocatalysis of sulfo and carboxy indigo dyes are suggested. The effect of hydroxide and carbonate anions on the rate of photocatalysis was also studied.

The kinetics of heterogeneous catalytic reductive amination of cyclopentanone has been studied on a pilot plant PARR autoclave. N-cyclopentyliminocyclopentane was detected as the main intermediate in a reaction mixture. It was found that, at the given conditions, the main intermediate does not form the undesirable N,N-dicyclopentylamine but undergoes slow hydrolysis, and the desired product, cyclopentylamine, results in a good yield. Slight amounts of by-products such as cyclopentanole and N,N-dicyclopentylamine were obtained. The experimental data were confronted with the suggested kinetic model.

Novel fluorescent N-glycoconjugates containing d-glucose, glycine and coumarin or naphthalenetriazole derivatives were prepared by peptide synthesis type methods. The fluorescence properties (spectra, quantum yields) of the compounds were evaluated.

Any kinetic description of a (photo)chemical reaction primarily involves a mathematical analysis showing how the concentration of the (photo)reactant depends on time. The desired dependence, namely the time dependence of concentration of (photo)reactant, is obtained by integration of differential rate equation. The simplest case of (photo)reaction is a (pseudo)monomolecular one. Unlike the kinetic model of (pseudo)monomolecular chemical reaction, the general analytical solution of mathematical model of photochemical reaction is, depending on experimental conditions, much more complicated or even impossible. In the present study, an approximation of the integral kinetic description of (pseudo)monomolecular photolysis has been developed, using high conversion and polychromatic irradiation. It was found that the reaction rate of photolysis of the model compound used can be described by a simple exponential asymptotical equation with two parameters, a linear and an exponential one. The former parameter means the maximum reaction rate and also characterises an overlap of absorption spectrum of starting photo-reactant and the spectrum of incident light. The physical meaning of the latter one is, unfortunately, more complex. Unlike the linear parameter, the value of exponential parameter has to be optimised on basis of the measured dependence of concentration of photo-reactant on time. Integration of the empirical rate equation proposed gave a simple relationship between concentration and reaction time. Potassium ferrioxalate was used as a model photo-reactant. Its photolysis was carried out both in a differential through-flow and an annular integral reactor. Medium pressure Hg arc lamps were used as polychromatic light sources in both cases. The maximum conversion of ferrioxalate was about 90%. It is supposed that the model can be extended to account for any (pseudo)monomolecular irreversible photochemical reaction.

The solvent dependence of absorption and fluorescence spectra, fluorescence lifetimes (τFl), and quantum yields (qFl) of various 3-substituted benzanthrone derivatives have been investigated. A consistent correlation between fluorescence quantum yield and emitting state energy has been found that holds for all 6 derivatives in 11 solvents. The experimental data together with the results of semiempirical quantum chemical calculations indicate that the main quenching channel of the fluorescent S1(π,π*) excited state is intersystem crossing to an upper (n,π*) triplet state, TN. The rate constant and efficiency of intersystem crossing between these two states are strongly influenced by the substituent and by the solvent polarity, as both modulate the singlet state energy and the S1−TN energy gap. The rate constant of direct S1 → T1 intersystem crossing is small in most systems but appears to increase with a decrease in the energy of the S1 state.

Acetyl and tosyl derivatives of 4,4′-diaminostilbene-2,2′-disulfonic acid and their N,N′-dimethyl analogues were prepared. The course of syntheses was checked by HPLC and products were identified with NMR spectroscopy. Chemical stability was tested in phosphate buffers. Acidobasic properties of prepared substances were studied with potentiometric titration and also with absorption and fluorescence spectrophotometry. The fluorescence quantum yields of pure acidobasic forms were measured. The tosylamino derivative was found to behave as N-acid and in aqueous alkali medium exhibits a strong fluorescence. The pKA values were estimated.

Absorption and fluorescence spectra of N-(disubstituted-1,3,5-triazinyl)-3-aminobenzanthrones, 3-acetylaminobenzanthrone and 3-methoxybenzanthrone have been investigated. Excitation energies and the character of the first absorption band have been calculated by the PPP-MO method. Some data on substituent and solvent effects on fluorescence spectral position and quantum yields are reported. The connection between electron density distribution in the electronic ground and excited state, and spectroscopic properties of those compounds, is explained.