A net-based approach to coordination polymers

True crystal engineering of coordination polymers with useful structure-based properties by design remains a distant prospect. The exploratory, experimental net-based approach to the construction of coordination polymers described in this article has provided a few examples of structures obtained by design, but also serendipitously revealed numbers of unprecedented and interesting structures that were totally unexpected. Further work with coordination polymers can confidently be expected to provide many similar surprises. It is proposed that carefully designed connecting ligands capable of binding metal centres strongly and predictably at chelating sites may afford improved structural control in network assembly and more robust network structures.