title: X-ray studies on anti-tumour triazenes. Structures of 1-(4-carbamoylphenyl)-3,3-dimethyltriazene 1-oxide and 3,3-dimethyl-1-(4-nitrophenyl)triazene.
abstract: The molecular structures of the title compounds have been determined by X-ray crystallographic methods. The analyses revealed differences in the geometry, and by inference the bond delocalization in these two triazenes owing to the presence in the 1-oxide structure of an N-O bond. The geometries are compared to the crystal structures of the isomeric 3-oxides [Kuroda & Wilman (1985). Acta Cryst. C41, 1543-1545; Neidle, Webster, Kuroda & Wilman (1987). Acta Cryst. C43, 674-676] which shows the dominance of an alternative tautomeric equilibrium for the triazene groups.
authors.affiliation: Cancer Research Campaign Biomolecular Structure Unit, The Institute of Cancer Research, Sutton, Surrey, England.
authors.forename: S
authors.initials: S
authors.lastname: Neidle
authors.forename: D E
authors.initials: DE
authors.lastname: Wilman
mesh_terms: D003196:Computer Graphics; D003497:Cyclic N-Oxides / Q000737:chemistry*; D003606:Dacarbazine / Q000737:chemistry; D008968:Molecular Conformation; D015394:Molecular Structure; D014226:Triazenes / Q000737:chemistry*; D014227:Triazines / Q000737:chemistry*; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D003497:Cyclic N-Oxides; D014226:Triazenes; D014227:Triazines; C076465:1-(4-carbamoylphenyl)-3,3-dimethyltriazene-1-oxide; C051647:1-(4-nitrophenyl)-3,3-dimethyltriazene; D003606:Dacarbazine