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  • 1
    Electronic Resource
    Electronic Resource
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 57 (2001), S. 651-652 
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Protopine hydrochloride (5,6,14,14a-tetrahydro-14a-hydroxy-7-methyl-8H-bis[1,3]benzodioxolo[5,6-a:4,5-g]quinolizinium chloride, C20H20NO5+·Cl−) is the salt of the isoquinoline alkaloid protopine. It is formed by the action of dilute hydrochloric acid on the protopine free base. The N-methyl and hydroxyl groups are in a trans configuration in the quinolizine ring and the central quinolizine N—C bond is unusually long [1.579 (2) Å]. The crystal is a racemate.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 37 (2000), S. 137-153 
    ISSN: 1573-1111
    Keywords: cyclosporin A ; X-ray structure analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A series of isomorphous clathrates(cyclosporin A: solvent = 1 : 1) is reported. Thestructure of the tetrahydrofuran (1) anddibutylether (2) clathrates have been determinedby X-ray single crystal diffraction. The cyclosporinmolecules in both structures are associated via vander Waals interactions forming cavities occupied bysolvent molecules. The structure refinement based onroom-temperature data sets show significant disorderof the side chains of the cyclosporin A molecule withno adequate model of the solvent molecule in bothstructures. In contrast, the position of dibutyletherwas successfully localised using a low-temperaturedata set for 2.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 104 (1971), S. 2044-2052 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Selenonation of Benzene and some of its Derivatives with Selenium TrioxideThe reaction of benzene and some of its derivatives with selenium trioxide in liquid sulfur dioxide produces mainly arylselenonic acids of the general formula RSeO3H (R = C6H5, p-Cl—C6H4, p-Br—C6H4, H3C—C6H4) together with small amounts of selenic acid and diarylselenones R2SeO2. The arylselenonic acids can be isolated in good yields via their barium salts.  -  The prepared products of selenonation were characterised by Debye-Scherrer diagrams, melting points, solubilities and i.r. spectra. The i.r. spectra of the diarylselenones are discussed.
    Notes: Durch Umsetzung von Benzol und einiger seiner Derivate mit Selentrioxid in flüssigem Schwefeldioxid entstehen neben Selensäure und kleineren Mengen von Diarylselenonen R2SeO2 überwiegend die Arylselenonsäuren RSeO3H (R = C6H5, p-Cl—C6H4, p-Br—C6H4, H3C—C6H4), die man über ihre Bariumsalze in guter Ausbeute isolieren kann.  -  Die dargestellten Selenonierungsprodukte werden auf Grund ihrer Debye-Scherrer-Aufnahmen, Schmelzpunkte, Löslichkeiten und IR-Spektren charakterisiert. Die IR-Spektren der Diarylselenone werden zugeordnet und diskutiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1995 (1995), S. 477-480 
    ISSN: 0947-3440
    Keywords: 1,3-Dipolar cycloadditions ; Nitrilimines ; Spiropyrazolines ; Lactones ; Cycloadditions ; Labeled compounds, 13C ; Calculations, AMI ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Substituted 4,5-dihydro-3-methylene-2(3H)-furanones 1 react as dipolarophiles with diphenylnitrilimine to give the corresponding spiro[furan-pyrazolin]ones 2. From the compound 1a, 1,3-diphenyl-7-oxa-1,2-diazaspiro[4,4]non-2-en-6-one (2a) is formed. In the other cases, a primarily formed cycloadduct undergoes rearrangement during the reaction to the bicyclic compound 5. Thus, addition of diphenylnitrilimine to (E)-1b, (Z)-1b and (E)-1c leads to compound 5b, whereas reactions of (E)- or (Z)-1f and (E)-1g give the corresponding compound 5f and 5g, respectively. The structure of 5b was determined by X-ray analysis. Labeled methyl formate (H13CO2CH3) was used for labeling the methylene carbon atom in 4,5-dihydro-3-(p-tosyloxymethylene)-2(3H)-furanone [(E)-1b] in order to ascertain the structure of the intermediate cycloadduct as well as the pathway of the consecutive rearrangement.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1147-1153 
    ISSN: 0044-2313
    Keywords: O,O′,O″,O‴-tetraphenyl μ-imido-dithiodiphosphate ; N-(O,O′-diphenylthiophosphoryl)-O″,O‴-diphenylthiophosphorimidate ; Bis(O,O′,O″,O‴-tetraphenyl μ-imido-dithiodiphosphato) palladium chelate ; Bis[N-O,O′-diphenylthiophosphoryl-O″,O‴-diphenylthiophosphorimidato] palladium chelate ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Der Tetraphenylester der μ-Imido-dithiodiphosphorsäure und sein Palladiumkomplex  -  KristallstrukturenDie Darstellung der Verbindung [(C6H5O2PS]2NH (SS) und ihres Palladiumkomplexes [Pd{C6H5O)2P(S)NP(S)(OC6H5) 2}2] (PDSS) wird beschrieben. Die Verbindungen werden elementaranalytisch, durch NMR- und Massenspektrometrie sowie mittels Röntgen-Kristallstrukturanalyse charakterisiert. Die Struktur von SS enthält zwei unabhängige Moleküle in einer asymmetrischen Einheit, die über N … H … S Wasserstoffbrücken zu Dimeren verbunden sind. SS ist eine Br⊘nsted-Säure, die mit PdII zu einem neutralen Chelatkomplex reagiert. Die Struktur von PDSS besteht aus isolierten Molekülen mit dem Pd-Atom als Symmetriezentrum. Das Pd ist an 4 S-Atome in einer verzerrt quadratisch-planaren Anordnung mit einem mittleren Abstand Pd—S von 2,345(6) Å und Winkel S—Pd—S von 98,29(4)° gebunden.
    Notes: The preparations of [(C6H5O)2PS]2NH (SS) and its Pd complex [Pd{C6H5O2P(S)NP(S)(OC6H5) 2}2] (PDSS) are described. The compounds were characterized by elemental analysis, NMR, and mass spectra and X-ray structure analysis. The structure of SS contains two independent molecules in an asymmetric unit which are joined into dimers via N … H … S hydrogen bonds. SS is a Br⊘nsted acid And reacts with PdII to a neutral chelate complex. The structure of PDSS is composed of isolated molecules with Pd atom in the center of symmetry. The Pd atom is coordinated by 4 S atoms in a distorted square-planar arrangement with average distance Pd—S 2.345(6) Å and an angle S—Pd—S 98.29(4)°.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0044-2313
    Keywords: O,O′,O″,O‴-tetraaryl-μ-imido-diphosphate ; O,O′,O″,O‴-tetraaryl-μ-imido- thiodiphosphate ; O,O′,O″,O‴-tetraaryl-μ-imido-dithiodiphosphate ; preparation ; crystal structure ; NMR investigation ; sign of P—P coupling constants ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tetraarylesters of μ-Imido-Diphosphoric Acid and its Thio Derivatives  -  Structure InvestigationsNew O,O′,O″,O‴-tetratolyl- and ditolyl-diphenylesters of the μ-imido-diphosphoric acid and its mono and dithio derivatives were synthesized, compared with the corresponding tetraphenylesters and investigated by 1H, 13C, and 31P NMR spectroscopy and X-ray crystal structure analysis. Structures of the O,O′,O″,O‴-tetrakis-(2-methyl-phenyl)-μ-imidodiphosphate, 1b, as well as of the corresponding ortho-, meta- and para-tolylesters of the μ-imido-monothiodiphosphoric acid (2a, 2b, 2c) were determined. All the compounds form dimers via N—H…O hydrogen bonds in the crystal as well as in nonpolar solvents. The distances around the phosphorus atoms rise with decreasing electronegativity of the phosphorus substituents. Signs of the 2JP—N—P coupling constants were determined by 13C{1H, 31P} triple resonance experiments for some compounds. These constants become more negative owing to substitution of a phosphoryl by a thiophosphoryl group.
    Notes: Neue O,O′,O″,O‴-Tetratolyl- und Diphenylditolyl-ester der μ-Imido-diphosphorsäure und ihres Monothio- und Dithioderivates wurden synthetisiert, in ihren Eigenschaften mit den bekannten Phenylestern verglichen und 1H-, 13C- und 31P-NMR-spektroskopisch untersucht. Die Kristall- und Molekülstrukturen des O,O′,O″,O‴-Tetrakis-(2-methyl-phenyl)-μ-imido-diphosphats, 1b, sowie der entsprechenden ortho-, meta-, und para-Tolylester der μ-Imido-monothiodiphosphorsäure (2b, 2c, 2d) konnten gelöst werden. Alle Verbindungen bilden über N—H…O-Wasserstoffbrücken Dimere, die auch in unpolaren Lösungsmitteln erhalten bleiben. Die Bindungsabstände um die P-Atome nehmen mit sinkender Elektronegativität der Substituenten zu. Durch 13C{1H, 31P}- Tripelresonanzexperimente wurde das Vorzeichen der 2JP—N—P- Kopplungskonstanten für einige Verbindungen bestimmt. Bei Substitution von Phosphoryl- durch Thiophosphorylgruppen werden diese Konstanten negativer.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1993 (1993), S. 1169-1173 
    ISSN: 0170-2041
    Keywords: Cycloadditions ; Nitrile oxides ; Spiroisoxazolines ; Lactones ; Dipolar cycloadditions ; Calculations, MNDO ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Benzonitrile oxide cycloadds to the C=C bond of substituted 4,5-dihydro-3-methylene-2(3H)-furanones 1a-1g. Thus, (E)-1a and (E)-1b are converted into the corresponding isoxazolinespirodihydrofuranones (4RS,5RS)-2a and (4RS,5RS)-2b, and (E)-1c is converted into a mixture of isomers (4RS,5RS)-2c and (4RS,5RS)-3c. The reactions of (E)-1d-1g yield mixtures of the corresponding diastereomeric isoxazolinespirodihydrofuranones (4RS,5RS,8RS)-2d and (4RS,5RS,8SR)-2d, (4RS,5RS)-3e and (4RS,5SR)-3e, (4RS,5RS)-3f and (4RS,5SR)-3f, (4RS,5RS)-3g and (4RS,5SR)-3g. The addition of benzonitrile oxide to (Z)-1a gives (4RS,5SR)-2a and 4a. In the cycloaddition with (E)-1a the p-tolylsulfonyloxy group in the intermediate (4RS,5RS)-2a is partially replaced by chlorine to give (4RS,5RS)-2h. - The structures of (4RS,5RS)-2h, (4RS,5RS)-3e, (4RS,5SR)-3e, and 4a are determined by X-ray analysis. The 1H- and 13C-NMR spectra of the products are discussed and the reaction course is rationalized on the basis of HOMO-LUMO energy gaps.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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