Search results for "antimony"
showing 10 items of 163 documents
Investigations on organoantimony compounds
1977
Abstract Trichlorodiorganoantimony(V) compounds, R2SbCl3, in which the antimony atom is part of a heterocyclic ring have been synthesized. They have been converted into the corresponding tetramethylammonium tetrachlorodiorganoantimonates, [R2SbCl4]− [Me4N]+, which are hexacoordinate diorganoantimony(V) species in which the antimony-carbon bonds are forced into a cis-position. 5,5,5-Trichlorodibenzostibole, 10,10,10-trichlorophenoxantimonin, 5,5,5-trichloro-5,10-dihydrodibenz[b, e]antimonin and 5,5,5-trichloro-10,11-dihydro-5H-dibenzo[b, f]stibepin have been prepared by chlorination of the corresponding heterocyclic chlorodiarylstibines. Heterocyclic trichlorodialkylantimony(V) compounds hav…
1H NMR spectra of Ph2SbX, PhSbX2, and Ph3SbX2 (XCl, Br, I); 121Sb Mössbauer spectra of PhSbX2 and crystal structure of Ph2SbI1
1996
1H NMR spectroscopic data of Ph2SbX, PhSbX2, and Ph3SbX2 (XCl, Br, I) have been determined by iterative simulation. 121Sb Mossbauer spectra of PhSbX2 (XCl, Br, I) have been measured. The synthesis of Ph2SbI is achieved by reaction of Ph2SbCl with NaI in ethanol. The crystal structure of Ph2SbI consists of molecules with pyramidal C2SbI units.
Size-selective incorporation of DNA nanocages into nanoporous antimony-doped tin oxide materials.
2011
A conductive nanoporous antimony-doped tin oxide (ATO) powder has been prepared using the sol-gel method that contains three-dimensionally interconnected pores within the metal oxide and highly tunable pore sizes on the nanoscale. It is demonstrated that these porous materials possess the capability of hosting a tetrahedral-shaped DNA nanostructure of defined dimensions with high affinity. The tunability of pore size enables the porous substrate to selectively absorb the DNA nanostructures into the metal oxide cavities or exclude them from entering the surface layer. Both confocal fluorescence microscopy and solution FRET experiments revealed that the DNA nanostructures maintained their int…
Zirconocene [Cp2Zr] synthon and benzynezirconocene complexes as tools in main group element chemistry
1998
Abstract Interactions between zirconocene or benzyne zirconocene and unsaturated species incorporating main group elements lead to a variety of new metallaheterocycles. Efficient new methodologies of regiospecific syntheses of mono-, bi-, or tricyclic systems incorporating phosphorus, nitrogen, selenium, antimony, germanium or tin are reported.
Speciation of Sb in airborne particulate matter, vehicle brake linings, and brake pad wear residues
2013
Insights into the speciation of Sb in samples of brake linings, brake pad wear residues, road dust, and atmospheric particulate matter PM10 and PM2.5 were obtained combining several well established and advanced characterization techniques, such as scanning electron microscopy e energy dispersive spectrometry (SEM-EDS), inductively coupled plasma mass spectrometry (ICP-MS) and synchrotron radiation X-ray absorption spectroscopy (SR-XAS). The advantage of SR-XAS is that samples do not undergo any chemical treatment prior to measurements, thus excluding possible alterations. These analyses revealed that the samples of wheel rims dust, road dust, and atmospheric particulate matter are composed…
Synthesis and structure of tetrakis(tetramethylammonium) octacosachlorooctaantimonate(III) [(CH3)4N]4Sb8Cl28
2000
Abstract The reaction between antimony trichloride and tetramethylammonium chloride in nitromethane gives transparent, irregular crystals of tetrakis(tetramethylammonium) octacosachlorooctaantimonate(III) [(CH 3 ) 4 N] 4 Sb 8 Cl 28 . Crystals are triclinic, space group P-1, a =11.846(2), b =12.217(2), c=14.120(3) A , α =95.71(3), β =101.39(3), γ =118.59(3)°, V=1713.7(5) A 3 , Z =1, d c =2.193, d m =2.17(2) Mg m −3 . The structure contains a structurally novel Sb 8 Cl 28 4- anion. It is composed of eight deformed octahedra, connected with each other by faces. In cavities formed by inorganic sublattice are located two crystallographically nonequivalent tetramethylammonium cations. One of them…
Solution synthesis of nanoparticular binary transition metal antimonides
2011
The preparation of nanoengineered materials with controlled nanostructures, for example, with an anisotropic phase segregated structure or a regular periodicity rather than with a broad range of interparticle distances, has remained a synthetic challenge for intermetallics. Artificially structured materials, including multilayers, amorphous alloys, quasicrystals, metastable crystalline alloys, or granular metals, are mostly prepared using physical gas phase procedures. We report a novel, powerful solution-mediated approach for the formation of nanoparticular binary antimonides based on presynthesized antimony nanoparticles. The transition metal antimonides M-Sb (M = Co, Ni, Cu(2), Zn) were …
Non-chromatographic speciation analysis of arsenic and antimony in milk hydride generation atomic fluorescence spectrometry
2003
Abstract A rapid, high sensitivity method has been developed for the determination of As(III), As(V), Sb(III) and Sb(V) in milk samples by using hydride generation atomic fluorescence spectrometry. The method is based on the leaching of As and Sb from milk through the sonication of samples with aqua regia followed by direct determination of the corresponding hydrides both before and after reduction with KI. It was confirmed by recovery experiments on spiked commercially available samples that neither the reduced nor the oxidized forms of the elements under study or mixtures of the two oxidation states were modified by the room temperature sample treatment with aqua regia. The methodologies …
Broadband Dielectric Investigation of Sodium Potassium Niobate Ceramic Doped 8% of Antimony
2012
In this work we present dielectric permittivity measurement results of KNN ceramic doped antimony (K0.5Na0.5)(Nb0.92Sb0.08)O3 with sintering aid MnO2 (0.5 mol% MnO2) (KNNSbx + 0.5Mn). Its dielectric properties were investigated in broad frequency (from 20 Hz to 32 GHz) and temperature (from 26 K to 780K) ranges. Above room temperature obtained results show two diffused phase transitions. Below room temperature investigation revealed dielectric permittivity dispersion similar to the relaxor one. The obtained mean relaxation times fulfills Arrhenius relationship with dipole activation energy Ea/kB = 2282 K.
Radical cation and dication of a 4H-dithieno[2,3-b:3′,2′-e][1,4]-thiazine
2017
A p-tert-butylphenyl substituted 4H-dithieno[2,3-b:3′,2′-e][1,4]thiazine was synthesized by twofold Buchwald–Hartwig coupling. The electronic properties (UV/Vis, cyclic voltammetry and spectroelectrochemistry) and the DFT- and TD DFT-calculated electronic structure reveal that the parent system and the radical cation and dication oxidation products are highly polarizable π-systems with strong charge transfer contributions. The radical cation and the dication were prepared by oxidation with antimony(V) pentachloride, giving stable deeply colored salts. EPR spectroscopy of the radical cation furnishes hyperfine coupling constants with the nitrogen nucleus and the α-thienyl protons. The dicati…