نتایج جستجو برای: hydrogen sulfate
تعداد نتایج: 202280 فیلتر نتایج به سال:
In the present of methylimidazolium hydrogen sulfate, the synthesis of arylidene heterobicyclic pyrimidinones is studied by condensation of aromatic aldehyde, cyclopentanone, and urea or thiourea. Using solvent-free conditions, non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are the advantages of this method.
Due to the importance and various applications of nitriles especially in medicinal productions, a new method for conversion of aldehydes to nitriles has been presented. Several nitrile-containing aromatic compounds were synthesized through the treatment of various aldehydes and hydroxylamine hydrochloride as nucleophile in the presence of ferric hydrogen sulfate as a heterogeneous, efficient, a...
An efficient, mild and environmentally friendly method was developed for the Strecker reaction to synthesize α-aminonitriles in the presence of methyl imidazolium hydrogen sulfate ([Hmim][HSO4]) as an efficient catalyst. These syntheses were performed via a one-pot three-component condensation of aldehydes (or ketones), amines, and trimethylsilyl cyanide under mild and solvent free c...
BACKGROUND The paper presents a quantification of main (hydrogen sulfide and sulfate), as well as of intermediate sulfur species (zero-valent sulfur (ZVS), thiosulfate, sulfite, thiocyanate) in the Yellowstone National Park (YNP) hydrothermal springs and pools. We combined these measurements with the measurements of quadruple sulfur isotope composition of sulfate, hydrogen sulfide and zero-vale...
In the present of methylimidazolium hydrogen sulfate, the synthesis of arylidene heterobicyclic pyrimidinones is studied by condensation of aromatic aldehyde, cyclopentanone, and urea or thiourea. Using solvent-free conditions, non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are the advantages of this method.
The environment of the Co(II) ion in the title compound, [Co(SO(4))(C(6)H(7)N)(2)(H(2)O)(2)](n), exhibits an octa-hedral configuration with the two 3-methyl-pyridine ligands lying in cis positions with respect to each other and trans to the two coordinated water mol-ecules. The axial positions are occupied by O atoms of the sulfate ions. Co and S atoms occupy special positions (twofold axis, Wy...
Geochemical, microbiological, and molecular analyses of alkaline saline groundwater at 2.8 kilometers depth in Archaean metabasalt revealed a microbial biome dominated by a single phylotype affiliated with thermophilic sulfate reducers belonging to Firmicutes. These sulfate reducers were sustained by geologically produced sulfate and hydrogen at concentrations sufficient to maintain activities ...
A furan-based hexaazamacrocycle encapsulates a sulfate anion in its cavity showing strong affinity and selectivity for sulfate in water over a wide range of inorganic anions. The DFT calculations demonstrate that the receptor provides binding sites as hydrogen bonding donors and electrostatic positive charges for the strong binding of sulfate.
Structural characterization of a sulfate complex with an azamacrocycle suggests that one sulfate is encapsulated in the macrocyclic cavity with eight hydrogen bonds; a significant selectivity of the host was observed for sulfate over halides, nitrate and perchlorate as evaluated by (1)H NMR studies in water.
Structural aspects of the binding of inorganic anions such as perchlorate, hydrogen sulfate, and hexafluorosilicate with the proton cage of octaaminocryptand L(1), N(CH(2)CH(2)NHCH(2)-p-xylyl-CH(2)NHCH(2)CH(2))(3)N), are examined thoroughly. Crystallographic results for a hexaprotonated perchlorate complex of L(1), [(H(6)L(1))(6+)(ClO(4) (-))]5(ClO(4) (-)).11H(2)O.CH(3)CN (1), an octaprotonated...
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