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AbstractAbstract
[en] We present an efficient and new preparative method for the symmetric β-diketimines assisted by microwave. A series of N,N'-symmetrically alkyl substituted β-diketimines have been synthesized from the reaction of O-acylation with dimethylsulfate. Higher reproducibility and yield, lower cost and much improved green nature originated from no solvent condition and higher energy efficiency due to faster reaction time are major merits of this new method. In addition to these merits, almost every kind of β-diketimines including alkyl-substituted β-diketimines little reported yet has been successfully prepared. Much wider applications of these compounds in various fields are expected
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Source
21 refs, 4 figs, 3 tabs
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Journal Article
Journal
Bulletin of the Korean Chemical Society; ISSN 0253-2964;
; v. 34(10); p. 2871-2876

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AbstractAbstract
[en] We have demonstrated the first examples of Mo(CO)6-mediated reductive S-O bond cleavage reactions of sulfoxides.We believe that this novel procedure will present a useful and attractive alternative to the existing methods for the deoxygenation of sulfoxides to sulfides. Further investigations of more useful applications are currently in progress. The deoxygenation of sulfoxides to sulfides is a valuable transformation in the application of organosulfur compounds in organic synthesis. Accordingly, a good number of methods have been developed for the reduction of sulfoxides to the corresponding sulfides. However, they often suffer from serious disadvantages, such as functional group incompatibility, difficult work-up procedures, harsh reaction conditions, or not readily available reagents. Further some of these methods are associated with limitations regarding low yields, prolonged reaction times, and intricate procedures
Primary Subject
Source
11 refs, 1 fig, 1 tab
Record Type
Journal Article
Journal
Bulletin of the Korean Chemical Society; ISSN 0253-2964;
; v. 28(2); p. 171-172

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AbstractAbstract
[en] Possibilities of using petroleum sulfides, sulfoxides and sulfones for extraction and separation of wide range of elements are considered. It is shown that petroleum sulfides appear to be effective and selective extractants in extraction and separation of noble metals (Ru, Au, Pt, etc.). Petroleum sulfoxides are promising for solvent extraction of transition metals, actinides, rare earths etc
Original Title
Solvent extraction of actinies, rare earths, transition metals
Primary Subject
Secondary Subject
Source
AN SSSR, Moscow (USSR); p. 305-309; 1988; p. 305-309; International solvent extraction conference; Moscow (USSR); 18-24 Jul 1988; 4 refs.; 2 figs.
Record Type
Miscellaneous
Literature Type
Conference
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AbstractAbstract
[en] Reactivity of innerspheric sulfide and thiol ligands in Nb, Mo, Ru complexes is considered. During interaction with cyanide ions disulfide ligand transforms to rhodanide one. With hydrogen evolution and formation of ethylenedithiolate bridge, sulfide and hydrosulfide complexes interact with unsaturated hydrocarbons. Sulfide, hydrosulfide and tiol ligands in the complexes undergo alkylation
Original Title
Reaktsionnaya sposobnost' sul'fidnykh i tiol'nykh ligandov; Complexes of Ru, Mo, Nb
Primary Subject
Source
p. 226-237; 1987; p. 226-237; Khimiya; Leningrad (USSR); 6 refs.
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Book
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AbstractAbstract
No abstract available
Original Title
Mesto sul'foksidov i sul'fidov v ryadu nejtral'nykh ehkstragentov i vozmozhnye oblasti ikh primeneniya; Extraction of rare earth compounds and transition element compounds
Primary Subject
Source
For English translation see the journal Sib. Chem. J.
Record Type
Journal Article
Journal
Izvestiya Sibirskogo Otdeleniya Akademii Nauk SSSR, Seriya Khimicheskikh Nauk; (no.7); p. 3-16
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AbstractAbstract
[en] Diallyltelluride reacts with ethane- and britan thiols under room temperature during 2 h with formation of sulfides (2) with ∼ 78% yield. Diallyltelluride conversion constitutes ∼ 93%. 9 refs., 1 tab
Original Title
Novaya reaktsiya diallilkhal'kogenidov s tiolami
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Journal Article
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AbstractAbstract
[en] The aim of this dissertation is to study some aspects of the electrochemical and radiation-chemical oxidation of sulphur compounds. Mechanistic investigations above all were carried out with regard to the sulphoxide formation. The electrochemical oxidation of the R-S- (CH2)n-S-R which occurs through an irreversible two-electron transfer in each case, supplied the lowest oxidation potentials for n=3. This is explained by a strong auxiliary group effect between the two sulphur atom as well as through the formation of a ring in the (S.S)-3e--bonded radical cation, which results from the oxidation. This result agrees well with radiation-chemical findings where the corresponding radical cation with n=3 shows the highest stability and yield. The dependence of the oxidation potential on the inductive effect through the substitutents R showed a linear relationship with negative increase, that is, the t-butyl-substituted compound is more difficult to oxidize than the methyl-substituted. Another factor favouring the oxidationof the methyl-substituted compound energetically, is the fact that an antibonding electron is removed in the case of the further oxidation of the radical cation to the dication. This electron in the case of the methyl-substituted radical cation is on a higher energy level and is easier to extract. The same behavior is observed in the oxidation of the compounds of the type X- (CH2)n-S-R (X=halogen). Here, too, with n(CH2)=3, the lowest potentials were found, that on account of the electronegativity of the halogen decline in the following sequence: Cl > Br > I. The dependence of the potential on the inductive effect of R corresponded to that of R-S- (CH2)3-S-R and was explained correspondingly. Sulphoxide was the main product of such irreversible oxidations, which was separated and identified by HPLC. (orig./BBR)
[de]
Ziel dieser Arbeit ist, einige Aspekte zur elektrochemischen und strahlenchemischen Oxidation von Schwefelverbindungen zu studieren. Insbesondere wurden mechanische Untersuchungen hinsichtlich der Sulfoxidbildung durchgefuehrt. Die elektrochemische Oxidation der R-S-(CH2)n-S-R, die jeweils durch einen irreversiblen Zwei-Elektronentransfer erfolgt, lieferte die tiefsten Oxidationspotentiale fuer n = 3. Erklaert wird dies durch eine starke Nachbargruppenwirkung zwischen den beiden Schwefelatomen sowie durch die Ausbildung eines Ringes im (S.S)-3e--gebundenen Radikalkation, welches bei der Oxidation entsteht. Dies steht in guter Uebereinstimmung mit strahlenchemischen Befunden, wo das entsprechende Radikalkation mit n = 3 die hoechste Stabilitaet und Ausbeute aufweist. Die Abhaengigkeit des Oxidationspotentials vom induktiven Effekt durch die Substituenten R ergab einen linearen Zusammenhang mit negativem Anstieg, d.h. die t-butyl-substituierte Verbindung ist schwerer zu oxidieren als die methylsubstituierte. Ein weiterer Faktor, der die Oxidation der methyl-substituierten Verbindung energetisch beguenstigt, ist die Tatsache, dass bei der Weiteroxidation des Radikalkations zum Dikation ein antibindendes Elektron entfernt wird. Dieses Elektron liegt im Falle des methyl-substituierten Radikalkations energetisch auf hoeherem Niveau und ist damit leichter 'herauszuloesen'. Das gleiche Verhalten erhielt man fuer die Oxidation der Verbindungen vom Typ X-(CH2)n-S-R (X = Halogen). Auch hier wurden bei n(CH2)= 3 die tiefsten Potentiale gefunden, die aufgrund der Elektronegavitaet des Halogens darueber hinaus in der Reihenfolge CI > Pr > I abnehmen. Die Abhaengigkeit des Potentials vom induktiven Effekt von R entsprach derjenigen von R-S-(CH2)3-S-R und wurde entsprechend erklaert. Als Hauptprodukt solcher irreversiblen Oxidationen wurde Sulfoxid ermittelt, das mit der HPLC getrennt und identifiziert wurde. (orig./BBR)Original Title
Vergleichende Untersuchungen zur elektrochemischen und strahlenchemischen Oxidation von organischen Sulfiden
Source
14 May 1991; 169 p; Available from FIZ Karlsruhe; Diss. (Dr.rer.nat.).
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Miscellaneous
Literature Type
Thesis/Dissertation
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AbstractAbstract
No abstract available
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Journal Article
Journal
Journal of Nuclear Science and Technology (Tokyo); v. 8(6); p. 302-308
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AbstractAbstract
No abstract available
Original Title
Soedineniya rodanida skandiya s piridinom
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Record Type
Journal Article
Literature Type
Progress Report
Journal
Zhurnal Neorganicheskoj Khimii; v. 16(1); p. 87-92
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AbstractAbstract
[en] The exact mechanism of SERS is still a matter of controversy, it is generally accepted that two enhancement mechanisms, one a long-range electromagnetic (EM) effect and the other a short-range chemical (CHEM) effect, are simultaneously operative. Both mechanisms suggest the possibility of the enhanced absorption and enhanced photochemistry for surface-adsorbed molecules. Direct observation of a surface-enhanced photochemical reaction has been reported. Aromatic sulfides such as benzyl phenyl sulfide and dibenzyl sulfide adsorbed on silver undergo surface reactions involving facile cleavage of C. S bonds by 514.5 nm radiation.5 As another example, 4-nitrobenzene-thiol and 4-nitrobenzoic acid adsorbed on silver are converted in ambient conditions to 4-aminobenzenethiol and 4-aminobenzoic acid, respectively, upon the irradiation of an Ar+ laser (514.5 nm).6-8 These molecules are found, however, not to undergo such reactions on a gold surface with visible light. This indicates that Ag substrates can act as moderate photoelectron emitters. In fact, the photoemission behavior of silver is known to be different in many aspects from that of other metals
Primary Subject
Source
18 refs, 3 figs
Record Type
Journal Article
Journal
Bulletin of the Korean Chemical Society; ISSN 0253-2964;
; v. 30(1); p. 242-244

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