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  • 29Si CP/MAS NMR  (1)
  • Copper(I) halides  (1)
  • Migration  (1)
  • Phosphorane  (1)
  • 1
    Electronic Resource
    Electronic Resource
    [Pt(dien)]2+ migrates intramolecularly from methionine S to imidazole Nz 2 in the peptides H-His-Gly-Met-OH and Ac-His-Ala-Ala-Ala-Met-NHPh (1999)
    Springer
    JBIC 4 (1999), S. 412-420 
    Details
    ISSN: 1432-1327
    Keywords: Key words Platinum(II) ; Migration ; Oligopeptides ; Methionine ; Histidine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The pH- and time-dependent reaction of [Pt(dien)(H2O)]2+ with the methionine- and histidine-containing peptides H-His-Gly-Met-OH and Ac-His-Ala-Ala-Ala-Met-NHPh at 313 K has been investigated by HPLC and NMR spectroscopy. For both peptides, initial relatively rapid formation of the kinetically favoured methionine S-bound complex is followed by slow intramolecular migration of the [Pt(dien)]2+ fragment to imidazole Nε 2 (or, in the case of H-His-Gly-Met-OH, to a much lesser extent to the competing imidazole Nδ 1) of the histidine side chain over a period of 500 h. Time-dependent studies for the pentapeptide at pH 8.0 demonstrate that this isomerization can take place by either direct S→Nε 2 migration or by a two-step mechanism involving initial Nε 2 coordination of a second [Pt(dien)]2+ fragment and subsequent cleavage of the orginal Pt-S bond in the resulting dinuclear complex. The rate of κS/κN ε 2 isomerization is markedly reduced on lowering the pH to 5.1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007750050327
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  • 2
    Electronic Resource
    Electronic Resource
    Stereochemie des intramolekularen Ligandenaustausches bei Derivaten des pentakoordinierten Phosphors: „Anti“-Berry-Verzerrungen in mono- und bicyclischen Phosphoranen (1980)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 304 (1980), S. 266-267 
    Details
    ISSN: 1618-2650
    Keywords: Phosphorane ; mono- und bicycl., Anti-Berry-Verzerrungen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00488810
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Tetramethylcyclotetraarsoxane Bridged Copper(I) Halides with Porous Sheet and Framework Structures ∞2[CuX{cyclo-(MeAsO)4}] (X=Cl, Br, I) and ∞3[Cu3X3{cyclo-(MeAsO)4}2] (X=Cl, Br) (1997)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 623 (1997), S. 1399-1406 
    Details
    ISSN: 0044-2313
    Keywords: Copper(I) halides ; tetramethylcyclotetraarsoxane complexes ; lamellar structures ; framework structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tetramethylcyclotetraarsoxan-verbrückte Kupfer(I)-Halogenide mit porösen Schicht- und Raumnetz-Strukturen ∞2[CuX{cyclo-(MeAsO)4}] (X=Cl, Br, I) und ∞3[Cu3X3{cyclo-(MeAsO)4}2] (X=Cl, Br)Offene Schicht- und Raumnetzstrukturen von ∞2[CuX{cyclo-(MeAsO)4}] (X=Cl, Br, I) 1-3 und ∞3[Cu3X3{cyclo-(MeAsO)4}2] (X=Cl, Br) 4 und 5 können durch Selbstorganisation aus CuX und Methylcycloarsoxan (MeAsO)n in Acetonitril erhalten werden. 1-3 bilden 44-Netze, in denen (CuX)2-Einheiten durch μ-KAs1 : 2 KAs3 - koordinierte (MeAsO)4-Liganden zu großen 28-zähligen Ringen verbunden sind. Im Gegensatz dazu sind parallel angeordnete ∞1[CuX]-Ketten in 4 und 5 durch μ4-K4As-koordinierte (MeAsO)4-Gruppen zu Schichten verbunden, die durch μ-1 kAs1 : 2 kAs3-Verbrückung mit (MeAsO)4-Cyclotetrameren zur Bildung einer porösen Raumnetzstruktur führen. 1-5 wurden mittels Röntgenstrukturanalyse charakterisiert.
    Notes: Open sheet and framework structures ∞2[CuX{cyclo-(MeAsO)4}] (X=Cl, Br, I) 1-3 and ∞3[Cu3X3{cyclo-(MeAsO)4}2] (X=Cl, Br) 4 and 5 may be prepared by self-assembly from CuX and methylcycloarsoxane (MeAsO)n in acetonitrile solution. 1-3 exhibit 44 nets in which (CuX)2 units are connected through μ-1 KAs1 : 2 KAs3 coordinated (MeAsO)4 ligands into large 28-membered rings. In contrast, adjacent ∞1[CuX] chains in 4 and 5 are connected into sheets by μ4-K4 As coordinated (MeAsO)4 building blocks, with μ-1 KAs1 : 2 KAs3 bridging of these layers by independent (MeAsO)4 cyclotetramers leading to the generation of a porous framework structure. 1-5 were characterised by X-ray structural analysis.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19976230914
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesen, Einkristall-Röntgenstrukturanalysen und 29Si-Festkörper-NMR-Untersuchungen eines zwitterionischen λ5-Spirosilicats und eines käfigartigen Octa(silasesquioxans)Professor Hartmut Bärnighausen zum 60. Geburtstage gewidmet (1993)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 347-358 
    Details
    ISSN: 0044-2313
    Keywords: Zwitterionic λ5-spirosilicate ; cage-like octa(silasesquioxane) ; Si—C cleavage reactions ; crystal structures ; 29Si CP/MAS NMR ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses, Single-Crystal X-Ray Analyses and Solid-State 29Si NMR Studies of a Zwitterionic λ5-Spirosilicate and a Cage-like Octa(silasesquioxane)The zwitterionic λ5-spirosilicate bis[2,3-naphthalenediolato(2 -)][2-(dimethylammonio)phenyl]silicate (1; isolated as 1 · 1/2 CH3CN) was synthesized by reaction of the [2-(dimethylamino)phenyl]dimethoxyorganosilanes 5, 6 and 7 [2-(Me2N)C6H4Si(OMe)2R: R = Ph (5), cyclo—C6H11 (6), Me (7)] with 2,3-dihydroxynaphthalene in acetonitrile at room temperature. Reaction of 1 · 1/2 CH3CN or [2-(dimethylamino)phenyl]trimethoxysilane (3) with water in acetonitrile yielded the cage-like octa{[2-(dimethylamino)phenyl]silasesquioxane} (2). The crystal structures of 1 · 1/2 CH3CN and 2 were studied by X-ray diffraction. In addition, 1 · 1/2 CH3CN and 2 were characterized by solid-state (29Si CP/MAS) and solution NMR studies (1H, 13C, 29Si).
    Notes: Das zwitterionische λ5-Spirosilicat Bis[2,3-naphthalindiolato(2 -)][2-(dimethylammonio)- phenyl]silicat (1; isoliert als 1 · 1/2 CH3CN) wurde durch Reaktion der [2-(Dimethylamino)phenyl]dimethoxyorganylsilane 5, 6 bzw. 7 [2-(Me2N)C6H4Si(OMe)2R: R = Ph (5), cyclo-C6H11 (6), Me (7)] mit 2,3-Dihydroxynaphthalin in Acetonitril bei Raumtemperatur synthetisiert. Durch Reaktion von 1 · 1/2 CH3CN bzw. [2-(Dimethylamino)phenyl]trimethoxysilan (3) mit Wasser in Acetonitril wurde das käfigartige Octa{[2-(dimethylamino)phenyl]silasesquioxan} (2) erhalten. Die Kristallstrukturen von 1 · 1/2 CH3CN und 2 wurden mittels Röntgenbeugung untersucht. Außerdem wurden 1 · 1/2 CH3CN und 2 durch Festkörper-NMR-Untersuchungen (29Si-CP/MAS) und NMR-Untersuchungen an Lösungen charakterisiert (1H, 13C, 29Si).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19936190220
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