Microporous networks co-assembled by both rigid and flexible building blocks

The porous networks of [Cu-2(malonato)(2)(bipy) (H2O)(2)] . H2O (I) and [Cd(malonato)(py)(H2O)] (II) were co-assembled by rigid 4,4'-bipyridine or pyridine and the flexible malonate: ion. In the network of compound I, 4,4'-bipy acts as a bone, separating and supporting the flexible malonate-Cu units to form a nearly strain-free square framework and a chiral square cavity in the solid state. In compound II, the rigid pyridine rings sustain the network by saturating the coordination sphere of Cd(II) ion to avoid a high coordination number and self-inclusion, and to prevent the two-dimensional network from forming a non-porous phase. (C) 2000 Elsevier Science Ltd All rights reserved.