Nucleobase Containing Synthetic Polymers: Advancing Biomimicry via Controlled Synthesis and Self-Assembly

The hydrogen-bonding recognition interactions of nucleobases are a fundamental property of nucleic acid chemistry and associated transcription, translation, and replication functions. Nucleobase interactions are central in protein biosynthesis, yielding sequence- and stereospecific macromolecules capable of assembly into precisely defined, complex shapes and morphologies that make up the machinery of life. As the understanding of nucleobases and their significance developed in the past century, chemists have inevitably sought to extend their function from a biological setting onto wholly synthetic platforms. Recent advances point to a burgeoning area of study which may soon bear fruit in some of the holy grails of polymer synthesis, namely sequence (and stereo) control, single chain manipulation, and controlled polymer folding. This Perspective seeks to summarize recent developments in the area of nucleobase containing polymers (including nucleobase mimics), with particular emphasis on controlled polymerization, self-assembly, and templating polymerization

Synthesis and Aggregation of Double Hydrophilic Diblock Glycopolymers via Aqueous SET-LRP

A chemically unprotected mannose-containing acrylate (ManA) monomer was synthesized and polymerized by Cu(0)-mediated radical polymerization in water (SET-LRP). One-pot block copolymerization was achieved upon addition of a solution of <i>N</i>-isopropylacrylamide (NIPAm) or diethylene glycol ethyl ether acrylate (DEGEEA) forming thermoresponsive double hydrophilic diblock glycopolymers which revealed self-assembly properties in aqueous solution forming well-defined, sugar-decorated nanoparticles

Aqueous Copper-Mediated Living Polymerization: Exploiting Rapid Disproportionation of CuBr with Me₆TREN

A new approach to perform single-electron transfer living radical polymerization (SET-LRP) in water is described. The key step in this process is to allow full disproportionation of CuBr/Me₆TREN (TREN = tris­(dimethylamino)­ethyl amine to Cu(0) powder and CuBr₂ in water prior to addition of both monomer and initiator. This provides an extremely powerful tool for the synthesis of functional water-soluble polymers with controlled chain length and narrow molecular weight distributions (polydispersity index approximately 1.10), including poly­(<i>N</i>-isopropylacrylamide), <i>N</i>,<i>N</i>-dimethylacrylamide, poly­(ethylene glycol) acrylate, 2-hydroxyethyl acrylate (HEA), and an acrylamido glyco monomer. The polymerizations are performed at or below ambient temperature with quantitative conversions attained in minutes. Polymers have high chain end fidelity capable of undergoing chain extensions to full conversion or multiblock copolymerization via iterative monomer addition after full conversion. Activator generated by electron transfer atom transfer radical polymerization of <i>N</i>-isopropylacrylamide in water was also conducted as a comparison with the SET-LRP system. This shows that the addition sequence of l-ascorbic acid is crucial in determining the onset of disproportionation, or otherwise. Finally, this robust technique was applied to polymerizations under biologically relevant conditions (PBS buffer) and a complex ethanol/water mixture (tequila)

A medieval farming glossary of Latin and English words Taken mainly from Essex records

SIGLEAvailable from British Library Document Supply Centre-DSC:3812.050(138) / BLDSC - British Library Document Supply CentreGBUnited Kingdo