ISSN:
1572-8854
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract Irradiation of uracil in ice produces a small quantity of thecis-anti cyclobutyl type photodimer. The molecule contains a pseudo two-fold axis and a cyclobutyl ring which is puckered, with dihedral angles near 150°. Torsion angles about the C(5)-C(6′) and C(5′)-C(6) bonds are 21°. Each uracil residue has seven atoms which are coplanar to within 0-07 Å, while C(6) and C(6′) are 0·38 Å and 0·35 Å out of the planes of their respective residues. Each molecule participates in eight NH...O bonds which range from 2·83 to 2·97 Å. The material crystallizes in the triclinic space group P¯1 with unit cell parametersa = 8·594 Å,b = 7·478 Å,c = 6·915 Å, α = 96·9 °, β = 95·4 ° and γ = 85·5 °. The structure was solved by means of the symbolic addition procedure for phase determination.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01197793
