T:Toxic;
11113-50-1Relevant academic research and scientific papers
Further studies of the tetraborane carbonyl B4H8CO
Spielman, John R.,Burg, Anton B.
, p. 1139 - 1145 (1963)
Tetraborane-8 carbonyl (B4H8CO) is made by the action of CO on either B4H10 or B5H11, suggesting the processes B4H10 → B4H8 + H2 and B5H11 → B4H8 + BH3. The reversal of these (significant for polyborane interconversion mechanisms) is shown by the high yields of B4H10 and B5H11 obtained when H2 or B2H6 reacts with B4H8CO. Basic reagents attack B4H8CO to form nonvolatiles without liberation of any CO; dimethyl ether and water behave so, and trimethylamine forms some (CH3)3NBH3. Ethylene also fixes the CO, in a slightly volatile unstable compound, (C2H4)4B4H8CO (structure uncertain), whereas BH3CO + 3C2H4 → (C2H5)3B + CO is quantitative. With excess PF3, B5H11 forms BH3PF3 and B4H8PF3, from the latter of which CO reversibly displaces PF3; in these reactions CO is not irreversibly fixed. In support of structural elucidation of B4H8CO by infrared and nuclear magnetic resonance spectra, B4D10, B5D11, and B4D8CO were made in nearly pure form. The structure of B4H8CO remains uncertain but the possibilities are limited. There may be a tautomeric equilibrium such that at least one H atom alternates between two B-H-B bridgings and a terminal B-H situation - much like the tautomerism of B5H11.
Architecture of lead oxide microcrystals in glass: A laser and etching based method
Almeida,Almeida,Hernandes,Mendon?a
, p. 5959 - 5964 (2016)
Lead oxide is an important glass modifier not only for affecting the chemical and mechanical stabilities of glasses, but also for improving their thermal and optical properties. Since specific properties are associated with the presence of PbO, its crystallization is important to enhance the material performance. Although considerable advances have been achieved regarding the fabrication of glass-ceramic from lead-based glasses, the spatial confinement of the crystallization remains challenging. Direct laser writing (DLW) has been considered an essential technique to overcome this issue, since material properties can be changed in localized and pre-determined regions. Although DLW with femtosecond laser pulses has been widely used for glass processing, its usage for phase transformations and control of the architecture of crystals has not been much exploited. This paper reports the design and control of β-PbO and 3PbO·H2O crystalline phases in a lead borate glass using fs-DLW followed by chemical etching at room temperature. We demonstrated that the etching in aqueous KOH solution is responsible for the glass crystallization, whereas the grooves produced by fs-laser pulses enable the selective crystallization in a pre-determined 2D pattern. The method described herein is important as it can control phase transformation at the micrometer scale and also permits the growth of lead oxide and lead oxide hydrate phases, which are not achieved by heat treatment. The morphologies of these microcrystals correspond to the structure of the respective compounds, being an octahedral euhedral crystal for 3PbO·H2O and thin sheets for β-PbO crystalline phases.
Neocarboranes, a new family of stable organoboranes isomeric with the carboranes
Grafstein, Daniel,Dvorak, Joseph
, p. 1128 - 1133 (1963)
Heating of the recently described compound2 carborane, C2B10H12, at 465-500° for 24 hr. produced the first member of a new family of organoboranes. The name neocarborane has been assigned to this product, which is isomeric with the original carborane. The chemistry ot neocarborane has been explored and is compared to that of carborane. In general, neocarborane derivatives are less polar and more stable than their carborane isomers. As in thecarboranes, the C2B10H10 unit is unusually inert and many standard organic processes can be effected on organofunctional substituents attached to the neocarborane carbon atoms. Carborane is assigned the distorted icosahedral structure, A, with the two carbon atoms sharing a short, depressed edge of an otherwise regular icosahedron. A regular icosahedral structure, C or D, is suggested for neocarborane. Electronic structures and possible reaction paths are indicated.
Complete dehydrogenation of hydrazine borane and hydrazine catalyzed by MIL-101 supported NiFePd nanoparticles
Yang, Kun,Yang, Kangkang,Zhang, Shiliang,Luo, Yan,Yao, Qilu,Lu, Zhang-Hui
, p. 363 - 371 (2018)
Trimetallic NiFePd nanoparticles (NPs) anchored on metal-organic framework (MOF) MIL-101 have been facilely prepared via a simple impregnation method. The as-prepared NiFePd/MIL-101 catalysts have been characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) equipped with energy dispersed X-ray detector (EDX) and selected area electron diffraction (SAED), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), N2 adsorption/desorption isotherms and X-ray photoelectron spectroscopy (XPS) techniques. And the as-synthesized catalysts have been applied for hydrogen generation from aqueous alkaline solution of hydrazine borane (HB, N2H4BH3). Compared to the pure Ni0.36Fe0.24Pd0.4 NPs, MIL-101 supported mono- and bi-metallic counterparts, the Ni0.36Fe0.24Pd0.4/MIL-101 catalyst exhibits much higher catalytic performance for complete conversion of N2H4BH3 to H2 with 100% selectivity at 323 K. The turnover frequency (TOF) value for the dehydrogenation of N2H4BH3 in the presence of Ni0.36Fe0.24Pd0.4/MIL-101 catalyst reaches 60 h?1. Remarkably, the Ni0.36Fe0.24Pd0.4/MIL-101 catalyst also shows high catalytic activity and 100% selectivity towards hydrogen generation from hydrous hydrazine (N2H4·H2O) at 323 K with a TOF value of 40.8 h?1. In addition, the durability tests exhibit that the Ni0.36Fe0.24Pd0.4/MIL-101 catalyst is still highly active in the complete dehydrogenation of N2H4BH3 and decomposition of N2H4·H2O with 100% hydrogen selectivity even after five recycles.
Kinetics and Mechanism of Hydrolysis of Some Amine-Cyanoboranes in Acid Perchlorate Media
Das, Mrinal Kanti,Bandyopadhyay, Soumendra Nath,Bhattacharyya, Siddhartha,Banerjee, Rupendranath
, p. 2929 - 2932 (1991)
In acid media (+> = 0.02-0.2 mol dm-3), isopropylamine- and diisopropylamine-cyanoborane are hydrolysed completely to boric acid, hydrogen, hydrogen cyanide and the salt of the corresponding amine.The reaction occurs in steps, viz.
Electrical and magnetic properties of nanocrystalline Fe100-xNix alloys
Vitta, Satish,Khuntia,Ravikumar,Bahadur
, p. 182 - 189 (2008)
The electrical and magnetic properties of nanocrystalline binary Fe100-xNix alloys, where x ranges from 0 to 100, prepared by a combination of aqueous and solid-state reduction processes have been studied vis-à-vis their microstructure. The microstructural studies indicate the formation of near-equilibrium phases in the alloys with crystallite size in the range 20-40 nm. The crystallite size in the case of pure Fe and Ni, however, is in the range 40-80 nm. The electrical transport in the temperature range 20-300 K exhibits a typical ferromagnetic metallic behavior in all the cases and the absolute resistivity of nanocrystalline Fe100-xNix alloys decreases monotonically with increasing Ni content. The saturation magnetization of the alloys on the other hand decreases progressively with Ni addition towards that of pure Ni value. The coercivity of alloys is found to be independent of temperature in the range 5-300 K except in the case of pure Ni wherein it increases from 30 Oe at 300 K to 65 Oe at 5 K. The electrical and magnetic properties of the nanocrystaline Fe-Ni alloys do not follow the predictions of simple itinerant band model for alloys. The temperature dependence of saturation magnetization in all the cases has a T3/2 Bloch variation while the average atomic moment of the alloys has an effective medium composition dependence.
Systematic study of Cr3+ substitution into octahedra-based microporous aluminoborates
Li, Qiaoqi,Lin, Cong,Zhou, Zhengyang,Ju, Jing,Li, Guobao,Lin, Jianhua,Gao, Wenliang,Cong, Rihong,Yang, Tao
, p. 5600 - 5608 (2014)
Single crystals of pure aluminoborate PKU-1 (Al3B 6O11(OH)5·nH2O) were obtained, and the structure was redetermined by X-ray diffraction. There are three independent Al atoms in the R3 structure model, and Al3 locates in a quite distorted octahedral environment, which was evidenced by 27Al NMR results. This distortion of Al3O6 octahedra release the strong static stress of the main framework and leads to a symmetry lowering from the previously reported R3 to the presently reported R3. We applied a pretreatment to prepare Al3+/Cr3+ aqueous solutions; as a consecquence, a very high Cr3+-to-Al3+ substitution content (50 atom %) in PKU-1 can be achieved, which is far more than enough for catalytic purposes. Additionally, the preference for Cr3+ substitution at the Al1 and Al2 sites was observed in the Rietveld refinements of the powder X-ray data of PKU-1:0.32Cr3+. We also systematically investigated the thermal behaviors of PKU-1:xCr3+ (0 ≥ x ≥ 0.50) by thermogravimetric-differential scanning calorimetry, in situ high-temperature XRD in vacuum, and postannealing experiments in furnace. The main framework of Cr3+-substituted PKU-1 could be partially retained at 1100 °C in vacuum. When 0.04 ≥ x ≥ 0.20, PKU-1:xCr3+ transferred to the PKU-5:xCr3+ (Al4B6O 15:xCr3+) structure at 750 °C by a 5 h annealing in air. Further elevating the temperature led to a decomposition into the mullite phase, Al4B2O9:xCr3+. For x > 0.20 in PKU-1:xCr3+, the heat treatment led to a composite of Cr 3+-substituted PKU-5 and Cr2O3, so the doping upper limit of Cr3+ in PKU-5 structure is around 20 atom %.
Preparation and properties of H2B2S5 and its decomposition products
Gates, Alfred S.,Edwards, Jimmie G.
, p. 2248 - 2252 (1977)
The preparation of solid H2B2S5 and its decomposition product H2S·xBS2, x = 4.84 ± 1.75, and observations of their properties by visual and chemical means and by x-ray, infrared, Raman, and mass spectrometry are reported. Metathioboric acid, (HBS2)3, was prepared by two methods and heated with sulfur in evacuated, sealed Vycor tubes to yield H2S·xBS2. Diiodotrithiadiborolane, I2B2S3, was prepared and treated with H2S to obtain H2B2S5 in benzene solution. Solid H2B2S5 decomposed and polymerized spontaneously to yield H2S·xBS2. X-ray, infrared, and Raman spectrometry revealed polymerization and extensive S-S bonding in the solid. Mass spectrometry of the vapor from the solid products gave predominantly H2B2S5+, H2S+, and their fragments at temperatures below 80°C and then high molecular weight ions up to B8S16+ at higher temperatures. Fragmentation of H2B2S5+ was shown to yield HBS3+ by identification of the corresponding metastable ion. A relationship of H2B2S5 to (BS2)n through polymerization and condensation is proposed.
Chemistry of boranes. VII. Octachlorononaborane-9 and its salts
Forstner,Haas,Muetterties
, p. 155 - 159 (1964)
Octachlorononaborane-9, B9Cl8H, is a volatile, solid pyrogenic product of H2B10Cl10·xH2O. In aqueous solution B9Cl8H is reduced to the dianion, B9Cl8H-2. Copyright 1964 by the American Chemical Society.
Boron carbide spherical particles encapsulated in graphite prepared by pulsed laser irradiation of boron in liquid medium
Ishikawa, Yoshie,Shimizu, Yoshiki,Sasaki, Takeshi,Koshizaki, Naoto
, (2007)
B4 C submicron particles were obtained by laser irradiation of B particles in ethyl acetate under atmospheric pressure and room temperature. Absorbed laser energy brought about B melting and decomposition of surrounding liquid medium molecules, leading to a reaction between the melted B and carbon species to form B4 C. Moreover, the obtained B4 C particles were encapsulated in a graphite layer. Such a graphite surface layer is useful for medical functionalization of particles. Thus, obtained B4 C particles encapsulated in graphite are expected to be promising agents for boron neutron capture therapy.
