Dynamic behaviour of a pseudo[ n]polyrotaxane containing a bipyridyl-based cyclophane: spectroscopic observations

• Published in: Polymer (Guilford) 1998-08, Vol.39 (17), p.3981-3991
• Main Authors: Mason, Philip E., Parsons, Ian W., Tolley, Malcolm S.
• Format: Article
• Language: English
• Subjects: Applied sciences; cyclophane; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; polymer; Properties and characterization; pseudopolyrotaxane; Solution and gel properties
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/S0032-3861(97)10053-2

We have shown by 1H n.m.r. spectroscopy that the equilibrium between the cyclophane 5,12,19,26[tetraazoniaheptacyclo[24.2.2.2 2,5.2 7,10.2 12,15.2 16,19.2 21,24]tetraconta2,4,7,9,12,14,16,18,21,23,26,28,29,31,33,35,37, 39-octa-decaene]tetrakis(hexafluorophosphate) ( 1) and the polymer [poly(1-(1,4,7-trioxadecenyl)-4-(11-(1-(5-oxynaphthyl)-1,4,7,11-tetroxaundecenyl))benzene)] ( B:N) n is both rapid and heavily weighted toward the formation of the pseudo[ n]polyrotaxane at room temperature in both MeCN-d 3 and DMSO-d 6. At room temperature in DMSO-d 6 there is about one ring upon the polymer for each two repeat units of ( B:N), at higher temperatures more repeat units are required to support one 1. At temperatures of ca. 243 K in MeCN-d 3 this system self assembles, by π stacking of the electron-rich polymer aromatics and the electron-poor cyclophane aromatics, into very ordered ‘rods’ that are on average about 10 nm long.