1-(p-carbamoylphenyl)-3,3-dimethyl-triazene, an antitumour agent.

In the crystal structure of the title compound, 4-(3,3-dimethyl-1-triazeno)benzamide, C9H12N4O, (2), the N = N double bond [1.282 (8) A] is 0.030 A shorter than the N--N single bond [1.312 (8) A], but both bonds are shorter than an isolated N--N single bond suggesting that there is double-bond character in each N--N bond, although it is unequally distributed. The molecule adopts a trans geometry around the N = N bond, but there is a significant deviation from planarity between the benzene ring and the plane of the triazene moiety. Compound (2) forms chains in the solid state in which the molecules are linked by C = O...H--N hydrogen bonds between carbamoyl groups. These chains are cross-linked into sheets by hydrogen bonding between the second N--H moiety and triazene units in adjacent chains.