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
    Neutral solvent/crown ether interactions, 4. Crystallization and low temperature (−150°C) structural characterization of 18-crown-6 · 2(CH3CN) (1988)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 6 (1988), S. 65-71 
    Details
    ISSN: 1573-1111
    Keywords: 18-Crown-6 ; C−H acidic hydrogen bonds ; acetonitrile ; low temperature crystal structure ; solvent complex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The crystal structure of 18-crown-6 · 2(CH3CN) has been determined via data collection at −150°C. The structure consists of two crown molecules each hydrogen bonded to two acetonitrile moieties in the asymmetric unit, each residing around a center of inversion. The crown ethers display their fullD 3d symmetry; methyl ... O contacts range from 3.189(8) to 3.598(8) Å. There are no close contacts indicative of any interaction between the crown/2(CH3CN) units.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00659370
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Neutral solvent/crown ether interactions 3. Reorientation of the hydrogen bonds in the low temperature (−150°C) structure of 18-crown-6·2(CH3NO2) (1987)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 5 (1987), S. 631-638 
    Details
    ISSN: 1573-1111
    Keywords: 18-crown-6, nitromethane ; solvent complex ; low temperature crystal structure ; C-H acidic hydrogen bonding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The title complex was crystallized from a saturated solution of 18-crown-6 in nitromethane at 5°C and cooled to −150°C prior to X-ray diffraction data collection. At −150° C 18-crown-6·2(CH3NO2) is monoclinic,P21/n witha=9.290(2),b=7.864(6),c=13.627(8) Å, β=1000.84(4)° andD calc=1.31 g cm−3 for Z=2. Leastsquares refinement using 1521 independent observed reflections [F o≥5σ(F o)] led to a final conventionalR value of 0.041. The complex at −150°C is isostructural with its room temperature structure with the exception of the orientation of the methyl hydrogen atoms and their crown ether oxygen interactions. The methyl group hydrogen atoms were fully refined isotropically. The crown ether resides around a center of inversion and hasD 3d symmetry. There is one methyl hydrogen...crown interaction at 2.35(3) Å, one apparently bifurcated hydrogen bond utilizing a second methyl hydrogen atom (2.55(3), 2.65(3) Å) and the third hydrogen atom is actually directed away from the crown ring (closest H...O contact=2.67(3) Å).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00663004
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Neutral molecule/crown ether interactions 5. Comparison of the C−H acidic interactions of nitromethane and acetonitrile with 18-crown-6 and dibenzo-18-crown-6. Crystal structures of dibenzo-18-crown-6·2 CH3NO2 and dibenzo-18-crown-6·2 CH3CN (1988)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 6 (1988), S. 629-645 
    Details
    ISSN: 1573-1111
    Keywords: Dibenzo-18-crown-6 ; acetonitrile ; nitromethane ; solvent complex ; low temperature crystal structure ; C−H acidic hydrogen interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Complete structural characterization of dibenzo-18-crown-6·2 CH3NO2 and dibenzo-18-crown-6·2 CH3CN have been carried out, including location and refinement of the methyl hydrogen atoms. Dibenzo-18-crown-6·2 CH3NO2 is monoclinic,P21/c, with (at −150°C)a=9.573(2),b=14.636(2),c=33.471(7) Å, β=93.77(2)°, andD calc=1.37 g cm−3 forZ=8. Interactions between the solvent methyl groups and the crown ethers and other solvent nitro groups associate the 1 : 2 complexes into polymeric chains alongb. The acetonitrile adduct exists as discreet 1 : 2 complexes in the solid state with C−H...O interactions exlusively to the ether. This complex is triclinic,P 1, with (at −150°C)a=9.458(6),b=9.570(5),c=14.404(5) Å, α=73.18(4), β=79.85(5), γ=66.82(6)°, andD calc=1.28 g cm−3 forZ=2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00656345
    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...