Single Chain Self-Assembly of Well-Defined Heterotelechelic Polymers Generated by ATRP and Click Chemistry Revisited

Well-defined heterotelechelic poly(styrene) carrying thymine/diaminopyridine (DAP) (Mn, SEC 9300, PDI 1.04) and Hamilton wedge (HW)/cyanuric acid (CA) (Mn, SEC 8200, PDI 1.04) bonding motifs are prepared via a combination of controlled/living radical polymerization and copper catalyzed azide/alkyne "click'' chemistry and are subsequently self-assembled as single chains to emulate-on a simple level-the self-folding behavior of natural biomacromolecules. Hydrogen nuclear magnetic resonance (H-1 NMR) in deuterated dichloromethane and dynamic light scattering analyses provides evidence for the hydrogen bonding interactions between the athymine and omega-DAP as well as alpha-CA and omega-HW chain ends of the heterotelechelic polymers leading to circular entropy driven single chain self-assembly. This study demonstrates that the choice of NMR solvent is important for obtaining well-resolved NMR spectra of the self-assembled structures. In addition, steric effects on the HW can affect the efficiency of the self-assembly process. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 2566-2576, 2011