Library

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
    Springer
    Journal of chemical crystallography 26 (1996), S. 607-613 
    ISSN: 1572-8854
    Keywords: Thiophene ; conjugated ene-ynes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The crystal structures of two conjugated ene-yne derivatives of thiophene are described, 2,5-di-(trimethylsilylethynyl)-3,4-dibromothiophene (1), is triclinic P $$\bar 1$$ witha=6.3281(4)Å,b=9.7421(6)Å,c=16.3669(9)Å; α=80.516(5)°, β=84.810(5)°, γ=74.072(5)°,Z=2,R=0.054; 2,3,4,5-tetra(trimethylsilylethynyl)thiophene (2), is monoclinic, P21/c with a=20.928(2)Å b=5.852(1)Å,c=23.907(2)Å; β=100.245(6)°,Z=4,R=0.049. The ethynylic C atoms of both compounds lie near the thiophene plane, with deviations in the range 0.010(3)–0.455(4)Å. The phenyl groups of2 form a dihedral angle of 13.0(4)°.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical crystallography 24 (1994), S. 811-813 
    ISSN: 1572-8854
    Keywords: Selenadiazole ; Cyclodecadiene ; conformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract 4,5,6,10,11,12-hexahydrocyclodeca[1,2-d∶6,7-d′]bis[1,2,3]selenadiazole, C10H12N4Se2, crystallizes in triclinic space group P $$\bar 1$$ witha=5.4625(3),b=7.2091(4),c=8.3122(6) Å, α=65.313(5), β=77.476(5), γ=77.442(5)°,V=287.35(4) Å3,Z=1. The structure was refined toR=0.031 andR w=0.030 for 2018 observed reflections. The molecule lies on an inversion center. The cyclodecadiene ring adopts an elongated chair conformation. The near-zero torsion angle of the elongated chair lies at the ring-fusion bonds, with a magnitude of 2.9(3)°. The five atoms of the selenadiazole ring exhibit maximum deviation 0.005(2) Å from planarity, with the adjacent carbon atoms lying respectively 0.020(2) and 0.059(2) Å to the same side of this plane. The torsion angles about the bonds comprising the sides of the elongated chair vary in magnitude from 61.0(2)° to 55.7(2)°. The cyclodecadiene C=C bond lengths are 1.368(2) Å. The selenium-carbon bond length is 1.850(2) Å. The Se−N distance is quite long, 1.888(2) Å.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical crystallography 29 (1999), S. 107-109 
    ISSN: 1572-8854
    Keywords: Guayulin B ; sesquiterpene ; bicyclogermacradiene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The sesquiterpene guayulin B, C23H30O3, 1, crystallizes with two independent molecules in monoclinic space group P21 with a = 18.099 (1), b = 6.0649(6), c = 19.126(1) Å, β = 100.82(1)°, V = 2062.1(5) Å3, and Z = 4. The double bonds of the cyclodecadiene ring are E, both methyl groups on the 10-membered ring are β-oriented. The cyclopropane ring at C6 and C7 also has the β orientation, while the anisoyloxy group is oriented α. The 10-membered rings of the two independent molecules have the same conformation as that of guayulin A.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...