Search results for "element"

Efficient palladium catalyzed synthesis of heteroaromatic sulfoxides

2007

Abstract The present Letter describes the efficient synthesis of novel heteroaromatic sulfoxides by means of a palladium catalyzed heteroarylation of sulfenate anions. Triazolopyridine, pyridine and thiophene sulfoxides can be obtained under mild conditions and in high yield from the corresponding heteroaryl bromides.

Leaving Group and Regioselectivity Switches in the Aminoalkylation Reaction of Indoles and Related Heterocycles with α-Amido Sulfones

2013

The regioselective aminoalkylation of indoles and related heterocycles with α-amido sulfones under basic conditions has been studied. The reaction that employed the MeMgBr/MgBr2 system provided high yields of 3-(1-carbamoylalkyl)indoles. On the other hand, the reaction that used Cs2CO3 afforded 1-(1-carbamoylalkyl)indoles exclusively in high yields. The first reaction constitutes a switch of the leaving group of the α-amido sulfone in comparison to previously reported reactions between indoles and α-amido sulfones, which provided 3-(1-arylsulfonylalkyl)indoles. The second reaction constitutes a switch in the regioselectivity. The extensions of these C- and N-aminoalkylations starting from p…

Evidence for the Formation of a RuIII−RuIII Bond in a Ruthenium Corrole Homodimer

2000

Complexes of tungsten (VI) with tartaric acid. Comparative study of the various schemes of formation

1981

The complex formation occurring between tungstic acid and tartaric acid has been investigated in order to explain the optical activity of tartaric acid in the presence of constant amounts of tungstic acid. A new scheme of formation that includes three different complexes is presented, which explains the experimental results found in the literature.

N,N-Dimethylformamide Diethyl Acetal

2001

(1; R1 = Et, R2 = Me) [1188-33-6] C7H17NO2 (MW 147.25) InChI = 1S/C7H17NO2/c1-5-9-7(8(3)4)10-6-2/h7H,5-6H2,1-4H3 InChIKey = BWKAYBPLDRWMCJ-UHFFFAOYSA-N (2; R1 = Me, R2 = Me) [4637-24-5] C5H13NO2 (MW 119.19) InChI = 1S/C5H13NO2/c1-6(2)5(7-3)8-4/h5H,1-4H3 InChIKey = ZSXGLVDWWRXATF-UHFFFAOYSA-N (3; R1 = PhCH2, R2 = Me) [2016-04-8] C17H21NO2 (MW 271.39) InChI = 1S/C17H21NO2/c1-18(2)17(19-13-15-9-5-3-6-10-15)20-14-16-11-7-4-8-12-16/h3-12,17H,13-14H2,1-2H3 InChIKey = JFIKHFNGAURIIB-UHFFFAOYSA-N (4; R1 = Et, R2 = Et) [22630-13-3] C9H21NO2 (MW 175.31) InChI = 1S/C9H21NO2/c1-5-10(6-2)9(11-7-3)12-8-4/h9H,5-8H2,1-4H3 InChIKey = AYZXEGOJMRKZCV-UHFFFAOYSA-N (mild and selective reagents for alkylation, f…

Validation of Methylmercury Determinations in Aquatic Systems by Alkyl Derivatization Methods for GC Analysis Using ICP-IDMS

2001

Isotope dilution mass spectrometry (IDMS), using an inductively coupled plasma quadrupole mass spectrometer (ICPMS) and a species-specific methylmercury spike was applied to validate the commonly used GC method for methylmercury (MeHg+) determination, which is based on the formation of volatile methylethylmercury by derivatization with NaBEt4. The spike compound, Me201Hg+, was synthesized by reaction of 201Hg-enriched mercury chloride with methylcobalamin. By analyzing different environmental aquatic samples, it was found that in most cases, transformation of MeHg+ into elemental mercury (Hg0) took place. From investigations of synthetic solutions, it could be followed that halide ions are …

Extraction Chromatographic Behavior of Rf, Zr, and Hf in HCl Solution with Styrenedivinylbenzene Copolymer Resin Modified by TOPO (trioctylphosphine …

2010

It is of great interest to study chemical properties of the transactinide elements with atomic numbers (Z) ≥ 104. One of the most important subjects is to establish the position of the elements at the extreme end of the periodic table. To this end we perform studies of chemical properties of these transactinides and compare them with those of their lighter homologues and with the ones expected from extrapolations in the periodic table. So far, chromatographic studies of the transactinides have provided experimental proof of placing rutherfordium (Rf, Z = 104) through hassium (Hs, Z = 108) into groups 4 to 8, respectively. 1-10 Quite recently, copernicium (Cn, Z = 112) has been shown to be a…

Synthesis, Structure, and Reactivity of the First Enantiomerically Pure Ortho-Metalated Rhodium(II) Dimer

1999

ChemInform Abstract: Continuous Hydrothermal Synthesis of Nanometric BaZrO3in Supercritical Water.

2008

Abstract Nanocrystalline barium zirconate (BaZrO 3 ) was synthesized using a hydrothermal synthesis process working in supercritical conditions and in a continuous way. By this method, we succeeded in the continuous and rapid production of nanopowders. As a preliminary work three barium precursors have been investigated: barium hydroxide (Ba(OH) 2 ), barium acetate (Ba(CH 3 COO) 2 ) and barium nitrate (Ba(NO 3 ) 2 ). Two of them (Ba(CH 3 COO) 2 and Ba(NO 3 ) 2 ) led to the pure perovskite phase. Then an experimental design has been conducted in order to determine the influence of the experimental parameters on the crystallinity and the grain size of the final product.

Slow Relaxation of the Magnetization in a {Co <sup>III</sup>Mn <sup>III</sup>} Heterometallic Brick-Wall Network

2021

The use of the cyanide-bearing dicobalt(III) complex (PPh 4 ) 2 [Co 2 III (m-2,5-dpp)(CN) 8 ] as a metalloligand towards [Mn(salen)(H 2 O)]ClO 4 afforded the heterobimetallic two-dimensional compound of formula [{Mn III (salen)} 2 {(m-NC) 4 Co 2 III (m-2,5-dpp)(CN) 4 }] n (1) [PPh 4 + = teraphenylphosphonium cation, 2,5-dpp = 2,5-bis(2-pyridyl)pyrazine and H 2 salen = N,N’ -ethylenebis(salicylideneimine)] whose structure has been determined by single crystal X-ray diffraction. Compound 1 exhibits a neutral brick-wall structure, where each [Co 2 III (m-2,5-dpp)(CN) 8 ] 2- unit adopts a tetrakis-monodentate bridging mode towards four {Mn III (salen)} + fragments through four of its eight cyan…