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

• Main Authors: Ken Cham-Fai Leung, Kwun-Ngai Lau, Wing-Yan Wong
• Format: Article
• Language: English
• Published: MDPI AG 2015-04-01
• Series: International Journal of Molecular Sciences
• Subjects: rotaxane; thermodynamic synthesis; dissociation; slippage; crown ether
• Online Access: http://www.mdpi.com/1422-0067/16/4/8254

A new [2]pseudorotaxane DB24C8É1-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 DB24C8É1-H·PF6 was stable at room temperature. The dissociation rate of [2]pseudorotaxane DB24C8É1-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 DB24C8É1-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.