A "Plug and Play" polymer through biocomplementary hydrogen bonding

Abstract

This article describes a DNA-like polymer that exhibits the ability to self-assemble through hydrogen bonding. We synthesized poly[1-(4-vinylbenzyl)thymine] (PVBT) and 9-bexadecyladenine (A-C16) through an atom transfer radical polymerization (ATRP) and alkylation, respectively. Biocomplementary PVBT/A-C16 hierarchical supramolecular complexes formed in dilute DMSO solution through nucleobase recognition, that is, hydrogen bonding interactions between the thymine (T) groups of PVBT and the adenine (A) group of A-C16; evidence for this molecular recognition was also gained from dynamic light scattering studies. H-1 NMR titration studies in CDCl3 showed that T-A complexes formed rapidly on the NMR time scale with high association constants (up to 534 M-1). Moreover, FTIR spectroscopic, differential scanning calorimetry, wide-angle X-ray diffraction, and small-angle X-ray scattering analyses provided further details into the nature of the self-assembly of these systems. In the bulk state, these complexes self-assemble into well-ordered lamellar structures; the changing d-spacing distance (ranging from 4.98 to 2.32 nm) at different A-C16 loadings reveals that the molecular structures of the PVBT/A-C16 complexes are readily tailored. (C) 2008 Wiley Periodicals, Inc.