Crystal structures of 2,5-di-azido-1,4-phenyl-ene di-acetate and 2,5-di-azido-1,4-phenyl-ene dibutyrate.

The asymmetric units of the title compounds, C10H8N6O4, (I), and C14H16N6O4, (II), each contain half of the respective mol-ecule which is completed by inversion symmetry. The two molecules differ in the ester moiety (acetate versus butyrate) and the crystal symmetry is different, i.e. triclinic for (I) and monoclinic for (II). The di-azido-phenyl-ene moieties are essentially planar [maximum deviation of 0.0216†(7)†à for (I) and 0.0330†(14)†à for (II)], and the ester functionalities are almost perpendicular to these planes, making dihedral angles of 79.93†(3)° for (I) and 79.42†(6)° for (II). In the crystals of both (I) and (II), there are no significant inter-molecular inter-actions present.