Supramolecular Pseudorotaxane Polymers from Biscryptands and Bisparaquats

J Am Chem Soc. 2018 Mar 28;140(12):4455-4465. doi: 10.1021/jacs.8b01480. Epub 2018 Mar 15.

Abstract

Five new bis(dibenzo-30-crown-10-based cryptand)s were synthesized, two of which (16 and 17) had long (12-atom), flexible spacers that led to cooperative complexation of dibenzyl paraquat TFSI ( Kave = 4.36 × 105 M-1 for 17•2b). Self-assembly of 16 and 17 with bisparaquats with similar spacers (18, 21, and 23) led to high molecular weight supramolecular pseudorotaxane polymers in solution. Continuous, flexible fibers were drawn from concentrated solutions. 17 with C10-linked bisparaquat 23 in dichloromethane (DCM) produced a log-log viscosity vs concentration plot with a limiting slope of 3.55, confirming high molecular weight; at 37 mM, the degree of polymerization was estimated to be 126 and Mn = 407 kDa. These are the first truly polymeric pseudorotaxane-type AA/BB supramolecular polymers.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.