ISSN:
1572-8854
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract Crystals oftrans-5-ethyl-5-(1′,3′-dimethylbut-1′-enyl) barbituric acid (13M1TB), mp 183° C, are triclinic witha = 7.677(2),b = 10.393(3),c = 9.176(3) Å, α = 104.331(1), β = 106.919(1), γ = 96.494(1)°, space group P, with two molecules in the unit cell. The structure was solved by direct methods and refined by least-squares procedures toR = 0.050 for 2809 observed diffraction maxima. The 5-ethyl group is oriented under the barbiturate ring with the orientation of the but-1-enyl group directed away from the ring. This orientation is determined by the 1′-methyl substituent. The molecules are linked together by N-H ... O=C hydrogen bonds across inversion centers, thus forming single ribbons alongb. Adjacent ribbons are held together in theac plane by van der Waals interactions between alternating ethyl and l′,3′-dimethylbut-l′-enyl groups.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01210388
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