Synthesis and Structure of Aminoguanidinium Sulfite Monohydrate

Abstract—The reaction between sulfur(IV) oxide and an aqueous suspension of aminoguanidinium hydro carbonate yields (CN4H7)2SO3 ⋅ H2O, an “onium” sulfite, which has been characterized by Xray diffraction and IR spectroscopy and mass spectrometry. The structure of the salt is stabilized by numerous Hbonds, such as NH⋅⋅⋅O, OH⋅⋅⋅O, and NH⋅⋅⋅N. The incorporation of pyramidal ions into the network of Hbonds is accompanied by the lowering of their symmetry in comparison with C3v, thus complicating the IR spectra of the salt in the region where the vibrations of the anion appear

Synthesis, Crystal Structure, Vibrational Spectra, and Thermochemical Transformations of Tris(hydroxymethyl)aminomethane

Abstract—A practically promising compound, tris(hydroxymethyl)aminomethane sulfate ((TRISH)2SO4, C8H24N2O10S) was synthesized and studied by a set of experimental methods (elemental analysis, IR and Raman spectroscopy, mass spectrometry, thermogravimetry)

Products of Interaction between Sulfur(IV) Oxide and Aqueous Solutions of Hexamethylendiamine and tertButylamine: The Crystal Structure of Hexamethylenediammonium Sulfate Dihydrate

The possibility of mild SO2 oxidation in sulfur(IV) oxide–alkylamine–water–oxygen systems is demonstrated to yield onium sulfates

Cs2Bi(PO4)(WO4)

Dicaesium bis­muth(III) phosphate(V) tungstate(VI), Cs2Bi(PO4)(WO4), has been synthesized during complex investigation in a molten pseudo-quaternary Cs2O–Bi2O3–P2O5–WO3 system. It is isotypic with K2Bi(PO4)(WO4). The three-dimensional framework is built up from [Bi(PO4)(WO4)] nets, which are organized by adhesion of [BiPO4] layers and [WO4] tetra­hedra above and below of those layers. The inter­stitial space is occupied by Cs atoms. Bi, W and P atoms lie on crystallographic twofold axes

Synthesis, Crystal Structure, and Spectral Characteristics of N-(tert-Butyl) aminomethanesulfonic Acid

A new method of the synthesis of N-(tert-butyl)aminomethanesulfonic acid in the system SO2–(CH3)3CNH2–CH2O–H2O was developed. The target compound [(CH3)3С]NHCH2SO3H was characterized by means of X-ray diffraction analysis, IR spectroscopy, and mass spectrometry

Interaction Products in the System Sulfur Dioxide–2,2′-Bipyridine–Water. Van der Waals Clathrates

Crystallization of 2,2′-bipyridine from aqueous solution containing sulfur(IV) oxide afforded clathrates with the composition (bipy)k·(SO2)m·(H2O)n. X-Ray amorphous guest SO2 molecules occupy voids in the crystal lattice of 2,2′-bipyridine without distortion of its structure. The isolated compounds were characterized by elemental analyses, X-ray diffraction data, and IR, NMR, and mass spectra

Characterization of commercial synthetic resins by pyrolysis-gas chromatography/mass spectrometry : application to modern art and conservation

To characterize a set of synthetic resins, a methodology by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) has been developed. The studied reference materials were commercial versions of a wide range of synthetic resins. For each polymer, the pyrolytic and chromatographic conditions were optimized to adequately resolve the fragment mixture in a short time. The proposed analytical method does not require previous treatment of the sample, and due to its high sensitivity, only a small sample quantity in the microgram range can be used. The pyrolysis temperature was found to have little effect on the obtained pyrograms. The summarized data set for the individual polymer materials, especially the characteristic fragments with a structure close to the monomeric unit, was useful to identify commercial synthetic resins. These materials were used in the art and conservation field, as binding media, paint additives, painting varnishes, coatings, or consolidants. Two case studies are introduced where direct Py-GC/MS and thermally assisted hydrolysis and methylation GC/MS were applied on art objects: first, a modern gluing material of a medieval reverse glass painting, and the second example, the binding medium of a painting by Georg Baselitz (“Senta”, 1992/1993) from the Sammlung Moderne Kunst at the Pinakothek der Moderne, MunichVersió editoria

Onium Salts of Sulfur-Containing Oxyanions Resulting from Reaction of Sulfur(IV) Oxide with Aqueous Solutions of 1,2-Diamines and Morpholine

Reaction products have been isolated from SO2–L–H2O–О2 systems (L = ethylenediamine, N,N,N',N'-tetramethylethylenediamine, piperazine, and morpholine) as onium salts [H3NCH2CH2NH3]SO4, [(CH3)2NHCH2CH2NH(CH3)2]SO4, [(CH3)2NHCH2CH2NH(CH3)2]S2O6 ⋅ H2O, [C4H8N2H4]SO3 ⋅ H2O, [C4H8N2H4]S2O6, [C4H8N2H4]SO4 ⋅ H2O, [O(C2H4)2NH2]2SO4 ⋅ H2O. The prepared compounds have been characterized by X-ray diffraction analysis, X-ray powder diffraction, IR and mass spectroscopy

Lifetime Measurement of the 6s Level of Rubidium

We present a lifetime measurements of the 6s level of rubidium. We use a time-correlated single-photon counting technique on two different samples of rubidium atoms. A vapor cell with variable rubidium density and a sample of atoms confined and cooled in a magneto-optical trap. The 5P_{1/2} level serves as the resonant intermediate step for the two step excitation to the 6s level. We detect the decay of the 6s level through the cascade fluorescence of the 5P_{3/2} level at 780 nm. The two samples have different systematic effects, but we obtain consistent results that averaged give a lifetime of 45.57 +- 0.17 ns.Comment: 10 pages, 9 figure