The application of a universal synthetic strategy for the high yielding and facile synthesis of a wide range of functional RAFT agents including trithiocarbonates, xanthates and dithiocarbamates is described.

Homopolymers of t butyl acrylate (P t BuA) and a monosubstituted acrylamide (PAM) having an amino acid moiety in the side chain, N-acryloyl-(L)-phenylalanine methyl ester 1, have been synthesized by Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization. Diblock copolymers of these homopolymers were also synthesized by chain extending P t BuA with monomer 1 and after modification, using simple acid deprotection chemistries of the acrylate block to afford a poly (acrylic acid) block, an optically active amphiphilic diblock copolymer was isolated. The optically active amphiphilic diblock copolymers, which contain chiral amino acid moieties within the hydrophobic segment, were then self-assembled to afford spherical micelles which were subsequently crosslinked throughout the shell layer to afford robust chiral nanoparticles. The hydrodynamic diameters (D h ) of the block copolymer micelles and nanoparticles were measured by dynamic light scattering (DLS) and the dimensions of the nanoparticles were determined using tapping-mode atomic force microscopy (AFM) and transmission electron microscopy (TEM). V V C 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: [3690][3691][3692][3693][3694][3695][3696][3697][3698][3699][3700][3701][3702] 2008

We present the synthesis of novel core reactive spherical polymeric micelles and nanoparticles using nitroxide mediated polymerization (NMP) techniques. These nanostructures have terpyridine functionality selectively located within their hydrophobic core domain and have been further modified by metal complexation (with Fe, Ru, and Cu) within this domain to afford novel metal functionalized polymer nanostructures. The hydrodynamic diameters (D h) of these micelles and hybrid nanoparticles were determined by dynamic light scattering (DLS), and the dimensions of the nanoparticles were characterized using transmission electron microscopy (TEM) and confirmation of the complexation was achieved using UV–vis analysis. The reactivity of the Cu-tethered metal complex within the nanostructures was investigated and was found to be an active catalyst for the 1,3-dipolar cycloaddition “click” reaction of azido and alkynyl functionalized small molecules. This strategy provides a versatile synthetic route toward the selective incorporation of active sites within the core domain of a polymer nanoparticle.

Reversible addition-fragmentation chain transfer (RAFT) polymerization techniques were utilized to polymerize N-acryloyl-L-phenylalanine methyl ester (L-Phe-OMe) and tetrahydropyranyl acrylate to afford amphiphilic star polymers (with 4 and 6 arms). These copolymer stars have a chiral hydrophobic core domain and can undergo further solution self-assembly to form well-defined nanostructures, which have been characterized using DLS, TEM, and cryo-TEM analysis. The characterization and properties of these novel chiral assemblies and their potential in racemic resolution are reported.

Optically pure N-acryloyl-(D)-leucine methyl ester (d-Leu-OMe) (1) and N-acryloyl-(L)-leucine methyl ester (l-Leu-OMe) (2) were synthesized and studied using infrared spectroscopy and melting point analysis to determine if d−l interactions are preferential relative to d−d or l−l interactions. Reversible addition−fragmentation chain transfer (RAFT) polymerization yielded enantiopure homopolymers of d-Leu-OMe (1) and l-Leu-OMe ester (2). The two enantiopure polymers, 5 and 6, and a 1:1 w/w racemic blend of both polymers were studied using infrared spectroscopy to investigate the intermolecular interactions in the polymeric systems. Poly(tert-butyl acrylate) [P(tBuA)] macro chain transfer agents were used to synthesize two diblock copolymers from 1 and 2, respectively. Subsequent deprotection of the P(tBuA) block to poly(acrylic acid) (PAA) yielded two chiral amphiphilic diblock copolymers, 7 and 8. Both enantiopure polymers were self-assembled separately and then in a 1:1 w/w ratio, and the resulting morphologies characterized using dynamic light scattering, atomic force microscopy, transmission electron microscopy, and circular dichroism.