(a) ORTEP drawing of [Zn(Hida)2]n·4nH2O (3), drawn with displacement ellipsoids at the 50% probability level. Free water molecules are omitted; (b) Schematic representation of 3-D diamondoid architecture by tetrahedral ZnII bridge in complex 3 viewed down the a axis (Zn: light blue, O: red, N: blue, C: gray, partial H atoms omitted for clarity).