MOLECULAR AND CRYSTAL-STRUCTURE OF N,N'-DIMETHYL-5,6-DIAMINOURACIL

The X-ray study of the crystal structure of N,N'-dimethyl-5,6-diaminou racil was performed. At 20 degrees C, a = 7.449(3), b = 11.459(4), and c = 10.048(4) Angstrom; beta = 102.52(2)degrees; V = 837(1) Angstrom( 3); sp. gr. P2(1)/n; Z = 4; and R = 0.051 for 1044 reflections, In the crystal, the compound exists as a monohydrate. The amino groups at th e C=C double bond are nonequivalent. Specific changes in the bond leng ths in the NH2-C=C-C=O moiety indicate strong conjugation between one of the amino groups and the adjacent carbonyl group. The other amino g roup is actually expelled from conjugation and has a trigonal-pyramida l configuration. The data obtained are correlated with the compound re activity.