Two new glycoluril derivatives, namely diethyl 6-ethyl-1,4-dioxo-1,2,2a,3, 4,6,7,7b-octa-hydro-5H-2,3,4a,6,7a-penta-aza-cyclo-penta-[cd]indene-2a, 7b-dicarboxyl-ate, C14H21N5O6, (I), and 6-ethyl-2a,7b-diphenyl-1,2,2a,3,4,6,7,7b-octa-hydro-5H-2,3,4a,6,7a-penta- azacyclo-penta-[cd]indene-1,4-dione, C20H21N 5O2, (II), both bearing two free syn-urea NH groups and two ureidyl C=O groups, assemble the same one-dimensional chains in the solid state running parallel to the [010] direction via N - H&mellip;O hydrogen bonds. Furthermore, the chains of (I) are linked together into two-dimensional network...
