Abstract
A supramolecular polymer was prepared from a mixture of poly(diallyldimethylammonium chloride) (1) and bis-ns-CB[10]. The repeat units of the polymer chain are capable of binding inside each of the two cavity domains of bis-ns-CB[10]. The bis-ns-CB[10] molecular containers complex the sides of the polymer chain – which we term a cupping interaction – thereby promoting the association of individual polymer strands to form 1 n √bis-ns-CB[10] m , which results in an extension of the length of the polymer. The effect of bis-ns-CB[10] on the physical properties of the polymer was investigated using viscometry in dilute aqueous solution. A decrease in ηrel was observed upon increasing the concentrations of bis-ns-CB[10] to a solution of 1. Atomic force microscopy and diffusion-ordered spectroscopy were performed to probe the mode of interaction between polymer 1 and bis-ns-CB[10]. Collectively, the data support the two roles for bis-ns-CB[10]: (1) as a deaggregation agent at lower concentrations and (2) as a cupping agent that non-covalently links individual polymer strands at higher concentrations resulting in overall extension of the polymer.
Acknowledgements
We would like to thank the members of the Scherman group for instructive conversations. We thank the National Science Foundation (CHE-0615049 and CHE-0829337 to LI), the Department of Education (P200A060238-07, GAANN fellowship to RN) and the UK Engineering and Physical Sciences Research Council (EP/F035535) and the Walters–Kundert Trust (OAS) for financial support.
Notes
†Dedicated to the memory of Prof. Dmitry Rudkevich