Mono- and Dinitro-BN-Naphthalenes: Formation and Characterization.
Ontology highlight
ABSTRACT:
SUBMITTER: Zhang MX
PROVIDER: S-EPMC8303104 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The sintering flue gas samples were collected at the inlets and outlets of the desulfurization systems to evaluate the influence of the systems on PCNs emission concentrations, profiles, and emission factors. The PCNs concentrations at the inlets and outlets were 27888-153672 pg m(-3) and 11988-42245 pg m(-3),respectively. Desulfurization systems showed excellent removal for PCNs, and the removal efficiencies of PCNs increase with increasing chlorination level. Lower chlorinated homologs are more sensitive to the desulfurization process than higher ones. High levels of PCNs were also detected in the gypsum (11600-29720 pg g(-1)) and fly ash samples (4946-64172 pg g(-1)). The annual total emissions of PCNs released to flue gas and gypsum from the sintering plants were about 394 kg, 48.5% of which was in gypsum. The surface area of the fly ash samples increased significantly from the first to the fourth stage of the series-connected electrostatic precipitator, accompanying obvious rising of concentration of PCNs in the fly ash samples.
| S-EPMC4873742 | biostudies-literature
Project description:The reaction of EuI2(THF)2 with potassium hydro-tris-(3,5-diiso-propyl-pyrazol-yl)borate (K[HB(3,5- iPr2pz)3] (= KTp iPr2, pz = pyrazol-yl) in a molar ratio of 1:1.5 resulted in extensive ligand fragmentation and formation of the europium(II) mono(scorpionate) complex bis-(3,5-diisopropyl-1H-pyrazole)[hydro-tris-(3,5-diiso-propyl-pyrazol-yl)borato]iodido-europium(II), [Eu(C27H46BN6)I(C9H16N2)2] or (Tp iPr2)(3,5- iPr2pzH)2EuIII, 1, in high yield (78%). As a typical by-product, small amounts of the sterically crowded pyraza-bole derivative trans-4,8-bis-(3,5-diiso-propyl-pyrazol-1-yl)-1,3,5,7-tetra-iso-propyl-pyraza-bole, C36H62B2H8 or trans-{(3,5- iPr2pz)HB(μ-3,5- iPr2pz)}2, 2, were formed. Both title compounds have been structurally characterized through single-crystal X-ray diffraction. In 1, two isopropyl groups are each disordered over two orientations with occupancy ratios of 0.574 (10):0.426 (10) and 0.719 (16):0.281 (16). In 2, one isopropyl group is similarly disordered, occupancy ratio 0.649 (9):0.351 (9).
| S-EPMC5730253 | biostudies-literature
Project description:The coordination chemistry of the 1,2-BN-cyclohexanes 2,2-R2 -1,2-B,N-C4 H10 (R2 =HH, MeH, Me2 ) with Ir and Rh metal fragments has been studied. This led to the solution (NMR spectroscopy) and solid-state (X-ray diffraction) characterization of [Ir(PCy3 )2 (H)2 (η(2) η(2) -H2 BNR2 C4 H8 )][BAr(F) 4 ] (NR2 =NH2 , NMeH) and [Rh(iPr2 PCH2 CH2 CH2 PiPr2 )(η(2) η(2) -H2 BNR2 C4 H8 )][BAr(F) 4 ] (NR2 =NH2 , NMeH, NMe2 ). For NR2 =NH2 subsequent metal-promoted, dehydrocoupling shows the eventual formation of the cyclic tricyclic borazine [BNC4 H8 ]3 , via amino-borane and, tentatively characterized using DFT/GIAO chemical shift calculations, cycloborazane intermediates. For NR2 =NMeH the final product is the cyclic amino-borane HBNMeC4 H8 . The mechanism of dehydrogenation of 2,2-H,Me-1,2-B,N-C4 H10 using the {Rh(iPr2 PCH2 CH2 CH2 PiPr2 )}(+) catalyst has been probed. Catalytic experiments indicate the rapid formation of a dimeric species, [Rh2 (iPr2 PCH2 CH2 CH2 PiPr2 )2 H5 ][BAr(F) 4 ]. Using the initial rate method starting from this dimer, a first-order relationship to [amine-borane], but half-order to [Rh] is established, which is suggested to be due to a rapid dimer-monomer equilibrium operating.
| S-EPMC4818983 | biostudies-literature
Project description:The asymmetric unit of the title compound, [Rb(C(7)H(3)N(2)O(6))(C(7)H(4)N(2)O(6))](n), comprises an Rb(+) cation, a 3,5-dinitro-benzoate anion and a 3,5-dinitro-benzoic acid ligand. The Rb(+) cation is nine-coordinated by O atoms from four 3,5-dinitro-benzoate anions and three neutral 3,5-dinitro-benzoic acid ligands. The metal atom is firstly linked by four bridging carboxyl groups, forming a binuclear motif, which is further linked by the nitro groups into a two-dimensional framework along the [110] direction. A short O-H?O hydrogen bond between two adjacent carboxy/carboxylate groups occurs.
| S-EPMC3212130 | biostudies-literature
Project description:The high-temperature plasma process has demonstrated great potential in growing high-quality boron nitride nanotubes (BNNTs) with small diameters (∼5 nm) and few walls (3-4 walls) and led to successful commercialization with a high production rate approaching 20 g/h. However, the process is still accompanied by the production of BN impurities (e.g., a-BN, BN shell, BN flakes) whose physicochemical properties are similar to those of BNNTs. This renders the post-purification process very challenging and thus hampers the development of their practical applications. In this study, we have employed both experimental and numerical approaches for a mechanistic understanding of BN impurity formation in the high-temperature plasma process. This study suggests that the flow structure of the plasma jet (e.g., laminar or turbulent) plays a key role in the formation of BN impurities by dictating the transport phenomena of BNNT seeds (e.g., B droplets), which play an important role in BNNT nucleation. We discussed that the turbulence enhances the radial diffusion of B droplets as well as their interparticle coagulation, which leads to a significant reduction in the population of effective BNNT seeds in the BNNT growth zone (T < 4000 K). This results in the generation of unreacted BN precursors (e.g., B-N-H species) in the BNNT growth zone that eventually self-assemble into BN impurities. Our numerical simulation also suggests that a higher thermal energy input makes the flow more turbulent in the BNNT growth zone due to the elevated velocity difference between the plasma jet and ambient cold gas. This finding provides critical insight into the process design that can suppress the BN impurity formation in the high-temperature plasma process.
| S-EPMC8529687 | biostudies-literature
Project description:Coumarin derivatives are a class of compounds with a pronounced wide range of applications, especially in biological activities, in the medicine, pharmacology, cosmetics, coatings and food industry. Their potential applications are highly dependent on the nature of the substituents attached to their nucleus. These substituents modulate their photochemical and photophysical properties, as well as their interactions in their crystalline form, which largely determines the final field of application. Therefore, in this work a series of mono and dihydroxylated coumarin derivatives with different chemical substituents were synthesized and characterized by UV-Visible spectroscopy, thermal analysis (differential scanning calorimetry (DSC) and TGA), 1H NMR and X-Ray Diffraction to identify limitations and possibilities as a function of the molecular structure for expanding their applications in polymer science.
| S-EPMC7436329 | biostudies-literature
Project description:A highly diastereoselective dearomatization of naphthalenes via a Pd-catalyzed 1,4-difunctionalization reaction is described. In the presence of a commercially available palladium precursor and ligand, intramolecular dearomative Heck-type insertion provides π-allylpalladium intermediates which are readily captured by a series of nucleophiles in excellent yields (up to 99%). This reaction features mild conditions, broad substrate scope, and useful transformations of the products.
| S-EPMC7504896 | biostudies-literature
Project description:Nowadays, boron nitride (BN) has attracted a great deal of attention due to its physical and chemical properties, such as high-temperature resistance, oxidation resistance, heat conduction, electrical insulation, and neutron absorption. The unique lamellar, reticular, and tubular morphologies and physicochemical properties of BN make it attractive in the fields of adsorption, catalysis, hydrogen storage, thermal conduction, insulation, dielectric substrate of electronic devices, radiation protection, polymer composites, medicine, etc. Based on this, we propose a novel method to produce boron nitride nanosheets (BNNSs) by a two-step method. The structure and morphology of the prepared BNNSs were characterized by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, XRD, FTIR, etc. The results showed that the prepared BNNSs had high crystallinity and the stripping efficiency of h-BN as well as the performance and yield of BNNSs had been improved, and the cost and environmental pollution of BNNS preparation had been reduced accordingly.
| S-EPMC8552327 | biostudies-literature
Project description:The tumor suppressor p53 is regulated by various posttranslational modifications including different types of ubiquitylation, which exert distinct effects on p53. While modification by ubiquitin chains targets p53 for degradation, attachment of single ubiquitin moieties (mono-ubiquitylation) affects the intracellular location of p53 and/or its interaction with chromatin. However, how this is achieved at the molecular level remains largely unknown. Similarly, since p53 can be ubiquitylated at different lysine residues, it remains unclear if the eventual effect depends on the position of the lysine modified. Here, we combined genetic code expansion with oxime ligation to generate p53 site-specifically mono-ubiquitylated at position 120. We found that mono-ubiquitylation at this position neither interferes with p53 ubiquitylation by the E3 ligases HDM2 and E6AP in complex with the viral E6 oncoprotein nor affects p53 binding to a cognate DNA sequence. Thus, ubiquitylation per se does not affect physiologically relevant properties of p53.
| S-EPMC9303418 | biostudies-literature
Project description:In the title mol-ecule, C(6)H(4)N(2)O(7), the two nitro groups are tilted with respect to the aromatic ring by 11.2 (1) and 10.9 (1)°. All three hy-droxy groups are involved in the formation of bifurcated intra- and inter-molecular O-H⋯O hydrogen bonds. The crystal packing exhibits short O⋯O distances of 2.823 (2) Å between two O atoms of the nitro groups.
| S-EPMC3295475 | biostudies-literature