ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Steric Control of Oxidative Trimerization of Alkynyl Ligands in Trimethylphosphane Palladium Complexes (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 343-350 
    Details
    ISSN: 0009-2940
    Keywords: Alkynes ; Palladium complexes ; Phosphane ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Alkynylpalladium compounds trans-PdX(C≡C—R)(PMe3)2 [R = CMe3, X = Cl (1), I (19); R = CMe2OH, X = Cl (2), Br (10), I (11); R = c-Hex, X = Cl (3), Br (12), I (13); R = CHMe2, X = Br (4); R = CH2SiMe3, X = Cl (5), Br (14), I (15); R = COOEt, X = Br (6), I (7); R = Ph, X = Cl (8), I (17); R = n-Pr, X = N3 (16), I (20); R = n-Hex, X = I (21); R = SiPh3, X = Br (22)] and trans-PdX(C≡C—R)(PBu3)2 [R = SiMe3, X = Cl (9), I (18)] as well as trans-PdX(C≡C—R)(PPh3)2 [R = CMe3, X = Br (23); R = CH2SiMe3, X = Br (24), I (25)] are prepared by known methods. Thermal decomposition between 120 and 160°C results in a selective transformation only with trimethylphosphane complexes 1, 2, 10-, and 19. Oxidative trimerization of the alkynyl groups C≡C—CMe2R′ and C≡C—(c-Hex) affording the enediynyl compounds trans-PdX[C(C≡C—CMe2R′) = C(C≡C—CMe2R′)CMe2R′] (PMe3)2 [R′ = Me, X = Cl (26), I (27); R′ = OH, X = Cl (28), Br (29), I (30)] and trans-PdX{C[C≡C—(c-Hex)]=C[C≡C—(c-Hex)] (c-Hex)}(PMe3)2 [X = Br (31), I (32)] appears to be controlled by balanced steric demands of phosphorus and alkynyl substituents. The steric control is investigated by melting) transformable monoalkynyl complex trans-PdI(C≡C—CMe2OH)(PMe3)2 (11) with non-transformable[*] complex trans-PdI[C≡C—(n-Pr)](PMe3)2 (20) to give a mixture (A) of transformed complexes with mixed substituents R. Similar results are obtained in other mixtures, when transformable PdBr(C≡C—SiMe3)(PMe3)[1] is heated with the non-transformable complexes PdBr[C≡C—(n-Pr)](PMe3)2[1] and 20 (mixture B) or transformable PdBr[C≡C—(c-Hex)](PMe3)2 (12) with non-transformable PdBr[C≡C—(n-Pr)](PMe3)2[1] (mixture C).
    Additional Material: 14 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280405
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Arsenidostannate mit Arsen-analogen [SnAs]-Schichten: Darstellung und Struktur von Na[Sn2As2], Na0,3Ca0,7[Sn2As2], Na0,6Sr0,6[Sn2As2], Na0,6Ba0,4[Sn2As2] und K0,3Sr0,7[Sn2As2] (1995)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 576-582 
    Details
    ISSN: 0044-2313
    Keywords: Arsenidostannates ; alkali - alkaline earth substitution ; [SnAs] nets isostructural grey arsenic ; crystal structure ; Zintl phases ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Arsenidostannates with [SnAs] Nets Isostructural to Grey Arsenic: Synthesis and Crystal Structure of Na[Sn2As2], Na0.3Ca0.7[Sn2As2], Na0.4Sr0.6[Sn2As2], Na0.6Ba0.4[Sn2As2], and K0.3Sr0.7[Sn2As2]The metallic lustrous compounds Na[Sn2As2], Na0.3Ca0.7[Sn2As2], Na0.4Sr0.6[Sn2As2], Na0.6Ba0.4[Sn2As2] and K0.3Sr0.7[Sn2As2] were prepared from melts of mixtures of the elements. The compounds crystallize in the trigonal system (space group R3m, No. 166, Z = 3) with lattice constants see in “Inhaltsübersicht”. The structures are isotypic to Sr[Sn2As2] containing puckered ∞2[SnAs] nets which are stacked with a sequence of six layers. The E(I)/E(II) atoms are located between each second ∞2[SnAs] layer in trigonal antiprismatic interstices formed by As atoms. In the resulting ∞2[Sn2As2] double layers the ∞2[SnAs] nets are stacked in such a way that additional Sn - Sn contacts arise.
    Notes: Die metallisch glänzenden Verbindungen Na[Sn2As2], Na0,3Ca0,7[Sn2As2], Na0,4Sr0,6[Sn2As2], Na0,6Ba0,4[Sn2As2] und K0,3Sr0,7[Sn2As2] wurden aus Schmelzreaktionen, ausgehend von Gemengen der Elemente erhalten. Die Verbindungen kristallisieren trigonal, Raumgruppe R3m (Nr. 166), Z = 3, mit den Gitterkonstanten (pm): TextNa[Sn2As2]a = 400,6(2)c = 2758,1(5)c/a = 6,885Na0,3Ca0,7[Sn2As2]a = 410,1(2)c = 2648,6(5)c/a = 6,458Na0,4Sr0,6[Sn2As2]a = 411,7(2)c = 2718,5(5)c/a = 6,603Na0,6Ba0,4[Sn2As2]a = 409,2(2)c = 2793,4(5)c/a = 6,826K0,3Sr0,7[Sn2As2]a = 417,6(2)c = 2714,6(5)c/a = 6,500 - In den im Sr[Sn2As2]-Typ kristallisierenden Verbindungen sind zum grauen Arsen isostrukturelle ∞1[SnAs]-Netze ausgebildet, die senkrecht zur c-Achse eine Sechserschichtfolge aufweisen. Jeder zweite ∞1[SnAs]-Schichtzwischenraum ist von E(I)/E(II)-Atomen in trigonal antiprismatischen Lücken aus As-Atomen belegt. In den resultierenden ∞2[Sn2As2]-Doppelschichtpaketen sind die benachbarten ∞2[SnAs]-Netze so zueinander orientiert, daß relativ kurze Sn - Sn-Kontake ausgebildet werden.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19956210415
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...