Kinetic and Thermodynamic Effects in the Self-Assembly of [3]Catenanes in the Solution and Solid States

✍ Scribed by David B. Amabilino; Peter R. Ashton; J. Fraser Stoddart; A. J. P. White; David J. Williams

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 284 KB
• Volume: 4
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/(sici)1521-3765(19980310)4:3<460::aid-chem460>3.0.co;2-#

✦ Synopsis

A change in the constitution of the tetracationic cyclophane components (comprised of two paraquat residues bridged by either m-or p-phenylene rings) in [2]catenanes, where the other macrocyclic components are polyethers (incorporating two p-electronrich rings, such as 1,4-dioxybenzene or 1,5-dioxynaphthalene, located symmetrically within a crown-10 structure) not only affects the efficiencies but also the selectivities associated with the selfassembly processes that lead to the formation of interlocked molecular compounds. The self-assembly of two new [2]catenanesÐcomposed of cyclo-(paraquat-p-phenylene ± paraquat-mphenylene) and either 1,5-dinaphtho-38-crown-10 (1/5DN38C10) or 1,5naphtho-p-phenylene-36-crown-10 (1/ 5NPP36C10)Ðis accompanied by the formation, in each case, of a [3]catenane incorporating a dimer of the tetracation-ic cyclophane and one or other of the two macrocyclic polyethers. A mechanistic rationale, based on thermodynamic and kinetic considerations, is presented to explain the formation of the dimeric octacationic products. The Xray crystal structures of the two [3]catenanes reveal the dominance of p ± p stacking interactions both within the molecules and beyond them where highly distinctive brick-like and parquet-like packing motifs are observed.