The synthesis of well-defined poly(vinylbenzyl chloride)-grafted nanoparticles via RAFT polymerization

• John Moraes,
• Kohji Ohno,
• Guillaume Gody,
• Thomas Maschmeyer and
• Sébastien Perrier

Beilstein J. Org. Chem. 2013, 9, 1226–1234, doi:10.3762/bjoc.9.139

• (VBC) shell nanoparticles. Optimal conditions for the control of VBC polymerization by RAFT are first established, followed by the use of the “grafting from” method to yield polymeric brushes that form a well-defined shell surrounding the silica core. We obtain particles that are monodisperse in size

• , and we demonstrate that the exceptional control over their dimensions is achieved by careful tailoring the conditions of the radical polymerization. Keywords: core–shell particles; free radical; grafting; RAFT polymerization; silica; Introduction The versatility of organic free radical chemistry in

• preparing highly monodisperse core–shell nanoparticles, which hold great promise for a range of applications such as drug-delivery vectors or colloidal-crystal self-assemblies [10][11]. RAFT polymerization initiated from preformed inorganic nanoparticles enables the grafting of polymer shells from the

Liquid-crystalline nanoparticles: Hybrid design and mesophase structures

• Gareth L. Nealon,
• Romain Greget,
• Cristina Dominguez,
• Zsuzsanna T. Nagy,
• Daniel Guillon,
• Jean-Louis Gallani and
• Bertrand Donnio

Beilstein J. Org. Chem. 2012, 8, 349–370, doi:10.3762/bjoc.8.39

• such as gel-permeation chromatography (GPC), or through a combination of these methods. Product purity and ligand-grafting rates and ratios can be determined through the use of techniques such as NMR spectroscopy, thermal analysis (DSC/TGA), elemental analysis, and other spectroscopic techniques (e.g

• , mesophase behaviour was reported for systems involving α-Fe2O3 NPs coated with mesogenic ligands containing a phosphonic acid anchoring group [59]. The NPs were prepared by using a sol–gel method, and grafting of the ligands was undertaken with 1:1 and 1:2 ligand/NP mass ratios. Mesogenic behaviour was

• into the smectic phase through another shift of c/2, followed by positional decoupling of the layers along the c axis (Figure 9). Interestingly, the important role of the alkylthiol coligand (referred to as the “primary grafting layer”) in determining the LC behaviour of these swallow-tailed hybrids

Synthesis of dye/fluorescent functionalized dendrons based on cyclotriphosphazene

• Aurélien Hameau,
• Sabine Fuchs,
• Régis Laurent,
• Jean-Pierre Majoral and
• Anne-Marie Caminade

Beilstein J. Org. Chem. 2011, 7, 1577–1583, doi:10.3762/bjoc.7.186

• [15]. The method elaborated is also useful for the grafting of dyes, as will be illustrated with the dabsyl dye. We also paid particular attention to the nature of the remaining function (usable for the grafting of the dendron). We choose an aldehyde and a primary amine, both being well-known for

• 31P NMR, which displayed in both cases the presence of one triplet and one doublet (2J (P,P) = 60 Hz), showing the unsymmetrical nature of these compounds. The next step involves the grafting of five equivalents of the dansyl phenol 3 on compounds 6 or 7, to afford dendrons 8 or 9, respectively. These

• were isolated in good yields after work-up (69.2 and 56.6%), and characterized by mass spectrometry and multinuclear NMR. The 31P NMR spectra generally consisted of multiplets, due to the non-symmetrical nature of these compounds. The aldehyde group is directly usable for grafting, as we have already

Coupled chemo(enzymatic) reactions in continuous flow

• Ruslan Yuryev,
• Simon Strompen and
• Andreas Liese

Beilstein J. Org. Chem. 2011, 7, 1449–1467, doi:10.3762/bjoc.7.169

• conversion to 90%. However, by adjustment of the residence time a continuous operation for 20 days was demonstrated. Covalent grafting of cofactors on soluble polymers for retention in continuously operating membrane reactors suffers from the disadvantage that enzymes often do not accept the cofactor

Efficient and selective chemical transformations under flow conditions: The combination of supported catalysts and supercritical fluids

• M. Isabel Burguete,
• Eduardo García-Verdugo and
• Santiago V. Luis

Beilstein J. Org. Chem. 2011, 7, 1347–1359, doi:10.3762/bjoc.7.159

• the enantioselective cyclopropanation with supported copper–bisoxazoline (Cu–BOX) or copper-pyridineoxazoline (Cu–PyOX) complexes and related systems. The oxazoline ligands can be introduced in polystyrene–divinylbenzene (PS–DVB) matrices either by grafting, by reaction with chloromethyl groups of

Stereoselectivity of supported alkene metathesis catalysts: a goal and a tool to characterize active sites

• Christophe Copéret

Beilstein J. Org. Chem. 2011, 7, 13–21, doi:10.3762/bjoc.7.3

• –inorganic materials [43], where surface functionalities such as typical organic ligands are perfectly distributed within the pore networks of a mesoporous silica. For other approaches used to prepare supported homogeneous catalysts, see the reviews [44][45][46]. Selective grafting of organometallic

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

• Daniel Crespy and
• Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

• molecules on the polymer, by the grafting of macromolecules or by degradation of the polymer. The functionalized polymer originates therefore from one or several reactive monomers or is the product of the transformation of a non-functional polymer to a functional polymer. The IUPAC recommendation for the

• droplets [46]. XPS measurements on dialyzed samples confirmed the grafting of the polymerizable surfactant onto the surface of the particles. Matahwa et al. synthesized one cationic and one anionic polymerizable surfactant and copolymerized these with styrene and methyl methacrylate by RAFT in miniemulsion

• vinyl monomers have also been reported [131]. In a first step, the polyaddition reaction was carried out between a polybutadiene terminated with hydroxy groups and the IPDI monomer in aqueous direct miniemulsion. The grafting of vinyl monomers on the PU backbone was then induced by γ-ray irradiation

Design and synthesis of a cyclitol-derived scaffold with axial pyridyl appendages and its encapsulation of the silver(I) cation

• Pierre-Marc Léo,
• Christophe Morin and
• Christian Philouze

Beilstein J. Org. Chem. 2010, 6, 1022–1024, doi:10.3762/bjoc.6.115

• complex is not water soluble (which precludes its use for biomedical applications) although the grafting of hydrophilic appendages to aromatic residues could increase its hydrophilicity. spatial representation of structure 1. structures of compounds 2–9. ORTEP drawing for the 1·Ag(I) cation complex

Formation of epoxide-amine oligo-adducts as OH-functionalized initiators for the ring-opening polymerization of ε-caprolactone

• Julia Theis and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 938–944, doi:10.3762/bjoc.6.105

• to start this side reaction. The significant increase of molecular weight in comparison with compound 4 was also confirmed by DLS measurements. As shown in Figure 6, the number-average hydrodynamic diameter increases after grafting from 1.45 nm (4) to 3.33 nm (6). The DSC curve of grafted compound 6

Hybrid biofunctional nanostructures as stimuli-responsive catalytic systems

• Gernot U. Marten,
• Thorsten Gelbrich and
• Annette M. Schmidt

Beilstein J. Org. Chem. 2010, 6, 922–931, doi:10.3762/bjoc.6.98

• the immobilization of amino functional targets are obtained in a single polymerization step by grafting-from copolymerization of an active ester monomer from superparamagnetic cores. The comonomer, oligo(ethylene glycol) methyl ether methacrylate, has excellent water solubility at room temperature

• our group [17][18][19]. Lately, hydrophilic brush shells have been described [31][32][33][34], prepared either by surface-initiated polymerization or by a “grafting to” approach of tailored copolymers from oligo(ethyleneglycol) methacrylates with adjustable and narrow flocculation temperature and low

Poly(glycolide) multi-arm star polymers: Improved solubility via limited arm length

• Florian K. Wolf,
• Anna M. Fischer and
• Holger Frey

Beilstein J. Org. Chem. 2010, 6, No. 67, doi:10.3762/bjoc.6.67

• strategy it is possible to combine high molecular weight with good molecular weight control (up to 16,000 g/mol, PDI = 1.4–1.7), resulting in PGA multi-arm star block copolymers containing more than 90 wt % GA. The successful linkage of PGA arms and PG core via this core first/grafting from strategy was

• initiating hydroxy groups was calculated from the degree of polymerization which is available from 1H NMR according to Equation 1. PG14 and PG38 thus offer an average of 17 and 41 potential initiating moieties for the grafting-from reaction with glycolide. It should be emphasized that according to Equation 1

• conducted in bulk without added solvent under Sn(Oct)2 catalysis with an average catalyst loading of 0.1 mol % of the glycolide feed. The mixed compounds yielded a homogeneous melt at 120 °C, fulfilling a prerequisite for an efficient grafting-from approach. Under the reaction conditions employed and taking

New amphiphilic glycopolymers by click functionalization of random copolymers – application to the colloidal stabilisation of polymer nanoparticles and their interaction with concanavalin A lectin

• Otman Otman,
• Paul Boullanger,
• Eric Drockenmuller and
• Thierry Hamaide

Beilstein J. Org. Chem. 2010, 6, No. 58, doi:10.3762/bjoc.6.58

• surface of the nanoparticles Results and Discussion Synthesis and characterization of the polymer surfactants Besides well-known functionalization of anhydride-based copolymers, the grafting of carbohydrate moieties on a polymer backbone by Huisgen [2 + 3] cycloaddition (CuI-catalyzed 1,3-dipolar

Functional properties of metallomesogens modulated by molecular and supramolecular exotic arrangements

• Alessandra Crispini,
• Mauro Ghedini and
• Daniela Pucci

Beilstein J. Org. Chem. 2009, 5, No. 54, doi:10.3762/bjoc.5.54

• Unità della Calabria, Dipartimento di Chimica, Università della Calabria, Via P. Bucci Cubo 14C, Arcavacata di Rende (CS), 87036, Italy 10.3762/bjoc.5.54 Abstract New concepts for the synthesis of metallomesogens have been recently developed in order to use the metal centre as a scaffold for grafting