Monitoring the thermody namically-controlled formation of diimide-based resin-attached rotaxanes by gel-phase HR MAS ~1H NMR spectroscopy

摘要

The thermodynamically controlled self-assembly of rotaxane and pseudorotaxane systems consisting of (ⅰ) a naphthodiimide thread unit terminated at one end with a pyridine ligand, and covalently linked at the other to a gel-phase polystyrene resin support, (ⅱ) a dinaphtho-crown ether shuttle unit, and (ⅲ) a ruthenium carbonyl metalloporphyrin stopper unit, is investigated by high resolution magic angle spinning proton (HR MAS ~1H) NMR spectroscopy. The effects of variable concentration of the solution-phase components, the temperature, and added Li~+ and Na~+ ions are described, and the limitations of the technique are addressed. The dynamic behaviour is compared directly to the solution-phase analogues, where a bulky stopper group is substituted for the polystyrene resin bead.