The preparation and crystal structure of 1,10,13,18-tetraazatricyclo[8.6.6.
0(3,8)]docosa-3,5,7-triene-11,17-dione monohydrate, C18H26N4O2. H2O, are de
scribed. The molecule has a U-shaped conformation, with the N atoms well or
iented for metal complexation.