Crystal structures of 4-amino-1,2,4-triazolidine-3,5-dione (urazine) (C2H4N4O2) and dichlorobis (4-amino-1,2,4-triazolidine-3,5-dione-N,O) copper (II) (C4H8Cl2CuN8O4)

Crystal structure analyses of urazine and of its adduct with CuCl₂ show that this ligand can exchange interactions of stacking that cannot be defined as simple - interactions. The copper atoms are octahedrally coordinated by two oxygen atoms and two aminic nitrogen from chelating uraxines and two chlorine atoms. The crystals of urazine are monoclinicP2₁c:a=6.741(1),b=5.815(1),c=11.141(2) Å,/gb=92.13(1)°,V_c=436.4(1) ų,Z=4,R=0.0402 for 714 independent observed reflections; the crystals of [CuCl₂(urazine)₂] are triclinicP¯1:a=5.236(1),b=6.662(1),c=8.411(1) Å,=93.00(1),=104.87(1), =105.69(1)°,V_c=270.66(8) ų,Z=1,R=0.0380 for 875 independent observed reflections.