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In this paper, we present the synthesis of new selenoloquinoxaline derivatives starting from 2‐chloroquinoxaline‐3‐carbonitrile 1. The compound 1 was subjected to a reaction with selenium metal in the presence of NaBH4 as a reducing agent in ethanol, under a nitrogen atmosphere. This reaction resulted in the formation of the sodium salt of 3‐cyanoquinoxaline‐2‐selenolate, which was subsequently reacted with α‐halogenated carbonyl compounds in situ. This reaction produced a series of newly synthesized 3‐aminoselenolo[2,3‐b]quinoxaline‐2‐substituents. Ethyl 3‐aminoselenolo[2,3‐b]quinoxaline‐2‐carboxylate 3a was hydrolyzed by sodium hydroxide to give the corresponding sodium salt 9. This salt was then refluxed with acetic anhydride to produce oxazinone compound 10. The reaction of compound 10 with ammonium acetate afforded pyrimidoselenolo[2,3‐b]quinoxaline derivative 11. Compound 11 was then chlorinated using phosphorous oxychloride to give the corresponding chlorocompound. [ABSTRACT FROM AUTHOR]

• A star-shaped phosphorus-nitrogen intumescent flame retardant (BTETP) based on triazine was synthesized. • BTETP was combined with ammonium polyphosphate (APP) to form intumescent flame retardants systems (IFRs) to flame-retard polypropylene. • Flame retardancy and thermal stability improved significantly by the combination of BTETP and APP. • Excellent flame retardancy can be achieved owning to condensed and gas phase synergistic flame-retardant mechanism. In this paper, a star-shaped char forming agent BTETP containing phosphorus and nitrogen is synthesized and characterized in the paper. It is compounded with ammonium polyphosphate (APP) to form an intumescent flame-retardant system. The stable star-shaped structure is constructed, and the insulating char layer is formed on the surface of the polymer matrix by the synergistic effect between phosphorus and nitrogen, thus, the high-performance flame retardant PP is obtained. Its flame retardancy and thermal stability are studied by limiting oxygen index (LOI), vertical combustion test (UL-94), cone calorimetry (CCT), and thermogravimetric analysis (TGA). With only a 20 wt% addition of BTETP/APP (1:2), the PP composite can reach the UL-94 v-0 level, while the peak heat release rate (PHRR), total heat release rate (THR), and average mass loss rate (AV-MLR) are significantly reduced compared with pure PP, showing higher fire safety. Moreover, the residue at 800 °C can reach as high as 9%, indicating that the loading of BTETP/APP is conducive to promoting carbonization of the degradation products of PP to generate more char. In addition, the synergistic effect and the flame retardant mechanism are studied and discussed. This study provides a program for the synthesis of flame retardants with a high-performance and effectively avoids the problem existing in traditional flame retarding approaches. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) are considered to be very promising group of chemicals and the number of their potential applications is growing rapidly. However, while these compounds were originally proposed as a green alternative to classical solvents, there are certain doubts as to whether this classification is correct. Although in recent years there have been first reports published proving the presence of some ILs in the environment and even in human blood, at this point the scale of this possible problem is not yet fully understood. However, there is no doubt that as the number of ILs applications increases, analytical capabilities for rapid detection of possible environmental contamination should be also considered. Therefore, in this review paper, recent evidences for the ILs environmental contamination as well as analytical achievements related to the extraction of ILs from various environmental matrices have been summarized and important gaps and future perspectives have been pointed out. Based on the presented data it might be concluded that there is the urgent need for further development towards risk assessment of these potential environmental contaminants. [Display omitted] • ILs are beginning to be detected in different environmental matrices. • The most commonly studied ILs are the ammonium compounds. • The number of studies on the analysis of ILs in environmental matrices is limited. • Reliable methods for the determination of ILs in environmental matrices are needed. [ABSTRACT FROM AUTHOR]

This paper investigates the catalytic properties of the iridium catalysts supported on modified silicalite-1. Post-synthesis modification of silicalite-1, with solutions of ammonium compounds (NH4F and NH4OH), appeared to be an efficient method to generate the acidic sites in starting support. The modification of support led not only to changes in its acidity but also its porosity—formation of additional micro- and mesopores. The novel materials were used as supports for iridium. The iridium catalysts (1 wt.% Ir) were characterized by N2 adsorption/desorption measurements, temperature-programmed reduction with hydrogen (TPR-H2), H2 chemisorption, transmission electron microscopy (TEM), temperature-programmed desorption of ammonia (TPD-NH3), X-ray photoelectron spectroscopy (XPS) and tested in the hydrogenation of toluene reaction. The catalytic activity of iridium supported on silicalite-1 treated with NH4OH (higher porosity of support, better dispersion of active phase) was much higher than that of Ir supported on unmodified and modified with NH4F silicalite-1. [ABSTRACT FROM AUTHOR]