Crystal structure of a complex of acridine, cytosine and water (1:1:1).

X-ray structural analysis of a crystalline complex between acridine C(13)H(9)N, cytosine C(4)H(5)N(3)O, and water (1:1:1) has been completed. The cytosine and water molecules form a sheet-like structure through a series of hydrogen bonds. The acridine molecules are bound to this layer through a hydrogen bridge from the water to the ring nitrogen. The acridine molecules stack in a parallel fashion normal to the cytosine-water sheets, with an average interplanar spacing of 3.5 angstroms.