Long and Short Brick Network Architecture: Role of Water Molecules Acting as Three-Connecting Spacers

Crystallization of N-butyl-4-(3-(dimethylamino)-propylamino)-1,8-naphthalimide (1) from moist hexane affords the 1:1 hydrate,
1·H2O, which exhibits a strong intermolecular hydrogen bonding network leading to a not so commonly encountered “long and short brick”
architecture influenced by interspersed water molecules. In contrast, an analogous system, N-butyl-4-(2-(dimethylamino)-ethylamino)-1,8-naphthalimide (2), which crystallizes without the water molecule, does not display a long and short brick tiling pattern.