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1.
Kimmo Smolander Risto J?rnstr?m Annika Sajalinna 《Fresenius' Journal of Analytical Chemistry》1989,335(4):392-394
Summary The matric effect of boric acid was investigated in the determination of iron in the primary circuit coolant water of nuclear power plants by furnace atomic absorption spectrometry. The effect of boric acid was of particular interest. The method was applied during refuelling and maintenance periods and the results were used to interpret the chemical changes in the water.
Einfluß von Borsäure auf die Bestimmung von Eisen in Reaktorkühlwasser durch GF-AAS相似文献
2.
Reversed-phase LC-MS/MS is used to determine major estrogenic alkylphenol ethoxylates (APEOs) and their biotransformation products. It allows the simultaneous analysis of eight APEOs, alkylphenoxy carboxylates (APECs) and alkylphenols (APs) in sewage treatment plant (STP) effluents in the same extract after solid-phase enrichment on polymeric Oasis HLB. As precursor ions, [APEO + NH4]+, [APEC - H]- and [AP - H]- were monitored. Instrumental limits of detection (LOD) were 2-600 pg, corresponding to sample concentrations of 0.04-12 ng l(-1), without correction for overall method recoveries. Matrix-induced signal suppression during electrospray ionisation (ESI) and extraction as well as overall method recoveries were assessed and the suitability of deuterated surrogates as internal standards was evaluated. 相似文献
3.
Annika Niklasson Ingemar Kvarnström Björn Classon Bertil Samuelsson 《Molecules Online》1998,2(1):7-14
Phosphonomethyl substituted 2?,3?-Dideoxy-3?-C-hydroxymethylcytidines have been synthesized and evaluated for their anti HIV-1 activities. The sugar moiety was synthesized starting from (S)-5-hydroxymethylfuran-2-(5H)-one using photocatalyzed addition of methanol. Reduction of the lactone, condensation with silylated 4-methoxy-2(1H)pyrimidinone, followed by phosphonomethylation and deprotection gave the title compounds. The compounds were tested for inhibition of HIV-1 activity but did not show any significant antiviral activity. 相似文献
4.
Alexander Mutschke Annika Schulz Marko Bertmer Clemens Ritter Antti J. Karttunen Gregor Kieslich Nathalie Kunkel 《Chemical science》2022,13(26):7773
The four compounds A3MO4H (A = Rb, Cs; M = Mo, W) are introduced as the first members of the new material class of the transition oxometalate hydrides. The compounds are accessible via a thermal synthesis route with carefully controlled conditions. Their crystal structures were solved by neutron diffraction of the deuterated analogues. Rb3MoO4D, Cs3MoO4D and Cs3WO4D crystallize in the antiperovskite-like K3SO4F-structure type, while Rb3WO4D adopts a different orthorhombic structure. 2H MAS NMR, Raman spectroscopy and elemental analysis prove the abundance of hydride ions next to oxometalate ions and experimental findings are supported by quantum chemical calculations. The tetragonal phases are direct and wide band gap semiconductors arising from hydride states, whereas Rb3WO4H shows a unique, peculiar valence band structure dominated by hydride states.The synthesis, structures and electronic properties of the first four heteroanionic compounds containing both hydride and transition oxometalate ions are reported. 相似文献
5.
Dr. Mohd Nazish Dr. Mujahuddin M. Siddiqui Dr. Samir Kumar Sarkar Dr. Annika Münch Christina M. Legendre Dr. Regine Herbst-Irmer Prof. Dietmar Stalke Prof. Dr. Herbert W. Roesky 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(5):1744-1752
This work describes the synthesis and coordination behavior of a new mixed-donor ligand PhC(NtBu)2SiC6H4PPh2 ( 1 ) containing both silylene and phosphine donor sites. Ligand 1 was synthesized from a reaction of ortho-lithiated diphenylphosphinobenzene (LiC6H4PPh2) with chlorosilylene (PhC(NtBu)2SiCl). Treatment of 1 with Se and GeCl2 resulted in SiIV compounds 2 and 3 by selective oxidation of the silylene donor. This strong σ-donor ligand induces dissociation of CuCl and PhBCl2 leading to formation of ionic complexes 4 and 5 respectively. The reaction of 1 with ZnCl2 and AlCl3 resulted in the formation of chelate complexes 5 and 7 , respectively, while treatment with EtAlCl2 and GaCl3 forms monodentate complexes 8 and 9 . X-ray analysis of 4 showed that the copper is in the spiro center of the two five-membered rings. Moreover, the copper(I)chloride has not been oxidized but dissociates to Cu+ and [CuCl2]−. All the compounds are well characterized by mass spectrometry, elemental analysis, NMR spectroscopy, and single-crystal X-ray diffraction studies. 相似文献
6.
N‐Heterocyclic Silylenes in Boron Chemistry: Facile Formation of Silylboranes and Silaborinines 下载免费PDF全文
Annika Gackstatter Prof. Dr. Holger Braunschweig Dr. Thomas Kupfer Christian Voigt Dr. Nicole Arnold 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(46):16415-16419
Reaction of a N‐heterocyclic silylene (NHSi) with PhBX2 (X=Cl, Br) readily afforded six‐membered silaborinines through an insertion/ring expansion sequence. Increasing the sterics of the borane from phenyl to duryl enabled the selective generation and isolation of the highly colored silylborane intermediates. Theoretical studies on the mechanism and energetics of the silaborinine formation were fully consistent with the experimental observations. 相似文献
7.
Toluene has been identified as a novel carrier of xanthates. Their corresponding fragmentative precursors proved to behave efficiently in radical group transfer reactions. As examples, unprecedented S-tri/di-chloromethyl xanthates could be prepared, isolated and further used in radical additions to olefins. Their precursors (de-aromatized toluene upon which is grafted, at one end, a tri/di-chloromethyl-group and, at the other end, a dithiocarbonyl group) can also be used directly in the transfer of both groups to olefins. The re-aromatizing loss of toluene by radical initiated fragmentation of the precursors brings thus new opportunities to the chemistry of xanthates, exemplified here in the intermolecular additions to olefins of new S-tri/di-chloromethyl xanthates. 相似文献
8.
Analyse von Protease‐Inhibitor‐Interaktionen unter Nutzung evolvierbarer tricyclischer Microviridine
9.
10.
Knowledge of residence time is a critical aspect in developing control and material diversion strategies for continuous manufacturing processes in pharmaceutica... 相似文献