Polycatenation, polythreading and polyknotting in coordination network chemistry

The use of crystal engineering concepts has produced a variety of coordination networks, many of which exhibit novel and fascinating types of entanglements of individual motifs. This review analyses the structures of a number of entangled polymeric networks reported in these years by many groups. A topological classification of the different interlocked and interweaved species is attempted. Wide classes of polycatenated and polythreaded species have been recognized and other phenomena, as polyknotting (self-penetration) and interweaving of ID chains, are also discussed. Unexpected topological features and new linkages, that were previously overviewed, have been discovered, including the first examples of infinite Borromean links. (C) 2003 Elsevier B.V. All rights reserved.