Otherwise Unstable Structures Self-Assemble in the Cavities of Cuboctahedral Coordination Cages
作者:Felix J. Rizzuto、William J. Ramsay、Jonathan R. Nitschke
DOI:10.1021/jacs.8b07494
日期:2018.9.12
directed self-assembly of interlocked structures and coordination complexes in a set of metal-organic hosts. New homo- and heteroleptic metal complexes-species that cannot be prepared outside-form within the cavities of cuboctahedral coordination cages. When linear bidentate guests and macrocycles are sequentially introduced to the host, a rotaxane is threaded internally; the resulting ternary host-guest complex
Crown-ether- and porphyrin-attached gel-phase resins in thermodynamically controlled rotaxane assembly
作者:Kathleen M. Mullen、Ken D. Johnstone、Dilip Nath、Nick Bampos、Jeremy K. M. Sanders、Maxwell J. Gunter
DOI:10.1039/b816115a
日期:——
Results of gel-phase proton high resolution magic angle spinning (HR MAS) NMR spectroscopy are described for a systematic study of the reversible, thermodynamically-controlled assembly of surface-attached neutral rotaxanes and pseudorotaxanes based on a three-component system consisting of a naphthodiimide thread unit, a naphthalene crown shuttle, and metalloporphyrin stoppers. Further to the previous systems based on an immobilised thread unit, we report here on the alternative systems where firstly a crown shuttle unit, and secondly metalloporphyrin stopper units, are attached to polystyrene beads, with the other two rotaxane components supplied in the surrounding solution phases in each case. Variations in concentration, temperature, and the effects of the addition of alkali metal salts are investigated. Within some limitations imposed by the technique itself, these results confirm that for each of the single entities attached in turn to polystyrene beads, rotaxane formation parallels that observed in the analogous solution-phase systems.