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  • 1
    Electronic Resource
    Electronic Resource
    Self-Assembly of Substituted 6-Hydroxy-trans-3-hexenoic Acids - Formation of Extended Ribbon-Like Structures by Hydrogen Bonds (1996)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 129 (1996), S. 1029-1034 
    Details
    ISSN: 0009-2940
    Keywords: Hydrogen bonding ; Hydroxy carboxylic acids, self-assembly of ; Crystal engineering ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The substituted 6-hydroxy-trans-3-hexenoic acids 2a and 2b are prepared by an organometallic template reaction involving a sequence of CC coupling reactions between a CO2 equivalent, butadiene, and 3-cyclopenten-1-one or 3,4-diphenyl-3-cyclopenten-1-one, respectively. In the crystal 2a assembles to form an infinite ribbon-type structure, exhibiting an alternating array of 12 and 18 atom-containing loops. The former are each constructed by an alternating CO2H/OH/CO2H/OH sequence, originating from four different monomeric units, that are linked together by means of hydrogen bonds. Two complementary ribbons of 2a are connected by van der Waals interactions to form staples that constitute the microscopic building blocks of the true (2a)n structure in the crystal. Stacks of cyclopentene π bonds are oriented inside the columnar structure of 2a. Acid 2b also forms a related ribbon-like assembly in the solid state. Here the bulky 3,4-diphenylcyclopentadienylidene moieties are oriented laterally at the ribbons, and van-der-Waals interactions with adjacent ribbons construct a three-dimensional hydroxyhexenoic acid network.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19961290909
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  • 2
    Electronic Resource
    Electronic Resource
    Process and fiber spinning studies for the cellulose/paraformaldehyde/dimethyl sulfoxide system (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 485-494 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A cellulose pulp of about 550 D.P. was readily dissolved in a combination of (CH2O)x/DMSO to afford an initial 6/6/88 cellulose/(CH2O)x/DMSO composition solution. The concentration of formaldehyde was found to be a function of solution heating time and temperature. The solutions were microscopically free of gels and undissolved cellulose fibers. Cellulosic articles such as fibers and films are easily regenerated from these cellulose solutions in the presence of coagulants such as methanol or water. Fibers with high wet modulus, intermediate tenacity, and low elongations were produced from these regenerations systems. Fibers have been spun with conditioned and wet tenacities as high as 2.9 and 2.1 g/d, respectively, with wet modulus (at 5% elongation) as high as 1.3 g/d and solubility in 6.5% NaOH in the low range of 3.0%-15%. In many respects, these fibers are comparable to those produced in the viscose process. However, the low elongations of these fibers probably would not permit normal textile processing. The cellulose/(CH2O)x/DMSO solutions were modified with compounds containing reactive N—H functional groups which are known to react with excess formaldehyde to yield the corresponding N-methylol derivatives. However, the resulting fiber physical properties were not significantly improved compared to those obtained from unmodified cellulose solutions. Addition of acrylic acid derivatives such as methyl acrylate, butyl methacrylate, or acrylonitrile to the cellulose solutions did not result in the formation of the expected 1,4-type adducts.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070230218
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  • 3
    Electronic Resource
    Electronic Resource
    Atomgewichtsbestimmung von Wismut (1924)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 141 (1924), S. 82-94 
    Details
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es wurde in der vorliegenden Arbeit eine Methode ausgeführt, das Atomgewicht von Wismut zu bestimmen durch Verbrennung einer seiner organischen Verbindungen, des Triphenyls. Im besonderen bestand die Aufgabe darin, eiae brauchbare Darstellungsmethode des Ausgangsmaterials zu ermitteln, um dessen Verwendungsmöglichkeit für eine exakte Analyse zu prüfen. Wie oben gezeigt wurde, konnte die Reindarstellung des Wismuttriphenyls leicht durch Destillation im Hochvakuum erzielt werden, die, wie auch die Sublimation, als die besten Methoden der Reinigung anzusehen sind. Wir erhielten ein absolut reines, durch Schmelz und Siedepunkt identifiziertes Produkt. Die Destillation wurde so geführt, daß der Tiegel, indem das Destillat aufgefangen wurde, im Wägegläschen verschlossen werden konnte, ohne mit der Außenluft in Berührung zu kommen, so daß jede Gefahr einer Aufnahme von Luftfeuchtigkeit vermieden wurde. Eine Verdichtung von Gasen innerhalb des Wismuttriphenyls konnte ebenfalls nicht eintreten, da ja einerseits im Vakuum gearbeitet wurde, andererseits das Destillat zu einer kompakten Masse im Tiegel erstarrte, deren Oberfläche nur klein war. Die Verbrennung selbst, die in Tiegeln aus Quarzglas ausgeführt wurde, verlief leicht und einwandfrei mittels reinster Oxalsäure, die durch mehrmalige Sublimation leicht rein dargestellt werden konnte. Bezüglich des Wismutoxyds ist noch zu sagen, daß es völlig frei von Kohlenstoff war, und wie die Prüfung ergab, keine okkludierten Gase enthielt, auch keinen Unterschied in der Auswage zeigte, wenn es direkt oder erst nach Evakuierung gewogen wurde. Dadurch, daß das Oxyd wieder im RICHARDschen Einfallapparat im Wägegläschen verschlossen wurde, war auch jede Bildung von basischem Salz ausgeschlossen. Von großem Vorteil und für die Arbeit als solche sehr günstig war vor allem, daß die Einwage, die Verbrennung selbst und auch die Auswage in ein- und demselben Gefäß vorgenommen wurde.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19241410106
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  • 4
    Electronic Resource
    Electronic Resource
    Electron-Poor 2,3-Dihydro-1,3-diborolyl Ruthenium Compounds: Synthesis, Complexation, Oxidative Addition, Capping, and Stacking Reactions (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1685-1692 
    Details
    ISSN: 1434-1948
    Keywords: Boranes ; Ruthenium ; Sandwich Complexes ; Diboroles ; Triple-decker ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The addition products of lithium alkyls and the pentaalkyl-2,3-dihydro-1,3-diborole derivatives 5a-f react with [{(C5Me5)RuCl}4] and [{(C5Me4Et)RuCl}4] to form the violet sandwich compounds 2*c-f and 2∧c, f. These formally 16 VE complexes are in fact electron-poor 18 VE species, because a high-lying combination of σ(B-C) orbitals interacts with the dxz orbital of the Ru atom. Addition of tert-butyl isocyanide to 2*a, or 2*d leads to the isonitrile complexes 6*a, and 6*d, as indicated by the spectroscopic data and X-ray structure analyses. At low temperature the interaction of 2*a, c, or e with H2 yields the classic dihydride complexes 7*a, c, and e, respectively, which have been studied by NMR. Oxidative addition of H3B·THF to the ruthenium atom of 2*a or c, followed by a reductive elimination of H2 and migration of the boranediyl group gives the yellow closo-RuC3B3 ruthenacarboranes 8*a and 8*c, respectively. The reaction of [(C2H4)2RhCl]2 and 2*c generates the tetranuclear complex 9*c.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Group 5 Metal Complexes with Cyclooctatetraene: Formation and Characterization of (Butadiene)(cyclooctatetraene)(cyclopentadienyl)tantalum Systems (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1461-1466 
    Details
    ISSN: 1434-1948
    Keywords: Diene complexes ; η3-Cyclooctatetraene metal complex ; B(C6F5)3 addition ; Tantalum ; Bicyclo[5.1.0]octadienyl metal complex ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The [(η4-diene)(η5-RCp)TaCl2] complexes 6a-e (diene = butadiene, isoprene or 2,3-dimethylbutadiene; RCp = pentamethylcyclopentadienyl, methylcyclopentadienyl or cyclopentadienyl) react with cyclooctatetraene dianion (employed as [(cot)Li2]) to yield the (η4-diene)(η3-cyclooctatetraene)(η5-RCp)tantalum complexes 7. The η3-cot coordination was confirmed by an X-ray crystal structure analysis of the compound [(supine-s-cis-η4-C4H6)(η3-cot)(η5-Cp*)Ta] 7a. In solution, the cot ligand of all the complexes 7 is fluxional. Two isomers [supine and proneorientation of the (diene)CpTa subunit] were found for the (η4-butadiene)(η3-cot)CpTa system (7e/7e′ = 95:5). Complex 7e cleanly adds the organometallic Lewis acid B(C6F5)3 to yield the betaine system [(η4-C4H6){C8H8B(C6F5)3}Cp*Ta] 8, which contains a substituted bicyclo[5.1.0]octadienyl ligand.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Substituent-Dependent Formation of Supramolecular Aggregates of 6-Hydroxy-trans-3-hexenoic Acids in the Solid State (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 187-192 
    Details
    ISSN: 1434-193X
    Keywords: Hydroxyalkenoic acids ; Hydrogen bonds ; Crystal engineering ; Molecular assemblies ; Scanning force microscopy ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The substituted 6-hydroxy-trans-3-hexenoic acids 2-4 have been prepared by a template coupling reaction between (butadiene)zirconocene, W(CO)6, and cyclobutanone, cyclodecanone, or cyclododecanone, respectively, followed by hydrolytic/oxidative demetallation of the resulting metallacyclic zirconoxycarbene tungsten complexes. The hydroxyalkenoic acids 2-4 have been found to form two novel fundamental types of associated supramolecular structural arrays in the solid state through intermolecular hydrogen bonding, which have been characterized by X-ray diffraction analysis. The cyclobutanone-derived compound 2 exhibits an infinitely extending sheet-like structure, which is composed of symmetrically alternating interconnected 12- and 36-membered rings, each being constructed from the functional groups or frameworks of four individual molecules of 2. In contrast, the cyclodecanone-derived compound 3 adopts a ribbon-type structure composed of C2-symmetrically arranged symmetry-equivalent 15-membered rings, each containing the functionalities from three individual molecules of 2. On the basis of scanning force microscopy studies, the cyclododecanone-derived compound 4 would appear to have a similar structure in the solid state. The structural features of the molecular assemblies that are formed by intermolecular hydrogen bonding of compounds 2-4 in the solid state are selectively controlled by the size and favoured conformations of the spiro-anellated carbocyclic rings at C6 of the 6-hydroxy-trans-3-hexenoic acid carbon chain.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Formation of the [(s-trans-η4-Butadiene)TaCp*Cp]+ Cation and Its Reaction with Organic Carbonyl Derivatives (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1453-1459 
    Details
    ISSN: 1434-1948
    Keywords: Group-5 bent metallocene cation complexes ; (Butadiene)tantalocene cation ; (s-trans-η4-Butadiene)metal complex ; Ethene polymerization ; Metallocenes ; Homogeneous catalysis ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (Butadiene)TaCp*Cl2 (6) was treated with CpNa to yield (η2-butadiene)TaCp*CpCl (7). Subsequent reaction with [Cp2ZrCH3+][CH3B(C6F5)3-] resulted in transfer of the chloride ligand from tantalum to zirconium with formation of the [(s-trans-η4-butadiene)TaCp*Cp]+ cation [8, with CH3B(C6F5)3- anion]. Complex 8 was characterized spectroscopically and by an X-ray crystal structure analysis. The group-5 [(s-trans-η4-C4H6)TaCp*Cp]+ bent metallocene cation complex 8 reacts with ketones (acetone, adamantanone) to yield the corresponding seven-membered 2-tantalatetrahydrooxepine cation complexes (9, 10). 1-Cyanoadamantane reacts with 8 to yield the 2-tantala-3,6-dihydro-2H-azepine cation system 11. Activation of 8 with methylalumoxane gives an active ethene polymerization catalyst.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Studien in der Thiophenreihe. LV. 2-Methyl-3-äthyl- und 3-Methyl-2-äthylthiophen und Derivate (1940)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 545 (1940), S. 45-51 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.19405450107
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  • 9
    Electronic Resource
    Electronic Resource
    1,1-Dithiooxalsäurederivate als Liganden in Übergangsmetallkomplexen: Struktur von O-Methyl-1,1-dithiooxalato-bis(triphenylphosphin)kupfer(I) und -silber(I) (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 498-504 
    Details
    ISSN: 0044-2313
    Keywords: Thiooxalates ; 1,1-Dithiooxalate ; 1,1-Dithiooxalic ester ; transition metal complex ; Crystal structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,1-Dithiooxalic Acid Derivatives as Ligands in Transition Metal Complexes: Structure of O-Methyl-1,1-dithiooxalato-bis(triphenylphosphine)copper(I) and silver(I)Despite O-Alkyl-1,1-dithiooxalates are also tetradentate thioligands their tendency towards the formation of multi-nuclear bridged chelates as found for the basic 1,1-dithiooxalate does practically not exist because of derivatisation. The reaction with triphenylposphinemetal(I)-halogenides yields defined mono-nuclear mixed ligand complexes: O-Methyl-1,1-dithiooxalato-bis(triphenylphosphine)copper(I) (2) and silver(I) (1). X-ray analysis shows that both complexes (1 and 2) are isostructural and crystallize in the monoclinic space group P21/n: (Ph3P)2Ag(S2C2O2Me) (1) with a = 12.794(1), b = 21.314(4), c = 13.560(1) Å, β = 97.983(6)°, and (Ph3P)2Cu(S2C2O2Me) (2) with a = 12.622(1), b = 21.196(2), c = 13.426(1) Å, β = 96.533(7)°. These complexes are the first authentic examples of exclusively end-on coordinated thiooxalate.
    Notes: Obwohl potentiell auch vierzähnig, ist die Tendenz von O-Alkyl(bzw. Aryl)-1,1-dithio-oxalaten zur Ausbildung von Brücken in Mehrkern-Chelaten durch die Derivatisierung gegenüber dem Stammliganden 1,1-Dithiooxalat praktisch nicht mehr vorhanden. Durch Umsetzung mit Triphenylphosphinmetall(I)-halogeniden sind definierte einkernige Gemischtligandenkomplexe zugänglich. O-Methyl-1,1-dithiooxalato-bis(triphenylphosphin)kupfer(I) und -silber(I) konnten mittels Röntgenkristallstrukturanalyse strukturell gesichert werden. Beide Komplexe sind isostrukturell und kristallisieren in der monoklinen Raumgruppe P21/n: (Ph3P)2Ag(S2C2O2Me) (1), mit a = 12,794(1), b = 21,314(4), c = 13,560(1) Å, β = 97,983(6)° und (Ph3P)2Cu(S2C2O2Me) (2), mit a = 12,622(1), b = 21,196(2), c = 13,426(1) Å, β = 96,533(7)°. Diese beiden Komplexe sind die ersten strukturell gesicherten Vertreter mit ausschließlich end-on koordiniertem Thiooxalat.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200317
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  • 10
    Electronic Resource
    Electronic Resource
    Überraschende Reaktionen an O-Methyl-1,1-dithiooxalaten (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 505-508 
    Details
    ISSN: 0044-2313
    Keywords: O-methyl-1,1-dithiooxalate ; nucleophilic attack on dithiocarbon ; perthio ligand ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Surprising Reactions on O-Methyl-1,1-dithiooxalatesThe O-methyl-1,1-dithiooxalate ligand (i-dtoMe) reacts with metalII-acetylacetonates of d8 metal centers (NiII, PdII) forming mononuclear mixed ligand complexes with two remarkable aspects: The formation of a perthioligand, first time described for thiooxalates, and the first example of a nucleophilic attack of a CH-acidic compound (acetylacetonate) on dithiocarbon of coordinated dithiocompounds (here i-dtoMe). X-ray structure is shown for Ph4P[(ptoMe)Ni(i-dtoMeacac)].
    Notes: O-Methyl-1,1-dithiooxalat (i-dtoMe) reagiert mit Acetylacetonatkomplexen von d8-Metallen (NiII, PdII) unter Bildung von einkernigen Gemischtligandenkomplexen Ph4P[(ptoMe)M(i-dtoMeacac)] unerwarteter Konstitution. Durch Röntgenkristallstrukturanalyse des NiII-Komplexes konnte erstmals ein nukleophiler Angriff einer CH-aciden Verbindung (Acetylacetonat) am Dithiokohlenstoff einer koordinativ gebundenen Dithioverbindung (i-dtoMe) nachgewiesen werden.Gefunden wurde weiterhin die Entstehung einer Perthiogruppierung, die bisher für Thiooxalate bzw. deren Derivate unbekannt war.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200318
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