Revisiting the Formation and Tunable Dissociation of a 2Pseudorotaxane Formed by Slippage Approach

摘要

A new [2]pseudorotaxane >DB24C8⊃>1-H·PF6 with dibenzo[24]crown-8 (>DB24C8) crown ether-dibenzylammonium (>1-H·PF6) binding which was formed by slippage approach at different solvents and temperature, had been isolated and characterized by NMR spectroscopy and mass spectrometry. The [2]pseudorotaxane >DB24C8⊃>1-H·PF6 was stable at room temperature. The dissociation rate of [2]pseudorotaxane >DB24C8⊃>1-H·PF6 could be tuned by using different stimuli such as triethylamine (TEA)/diisopropylethylamine (DIPEA) and dimethyl sulfoxide (DMSO). In particular, the dissociation of [2]pseudorotaxane >DB24C8⊃>1-H·PF6 by an excess of TEA/DIPEA base mixture possessed a long and sustained, complete dissociation over 60 days. Other stimuli by DMSO possessed a relatively fast dissociation over 24 h.