C Christina Ott

Tuning block copolymer micelles by metal–ligand interactions

A terpyridine end-capped poly(styrene)-block-poly(tert-butylacrylate) (PS-b-PtBA-[) copolymer has been synthesized by nitroxide-mediated radical polymerization using a terpyridine-functionalized initiator. Micellization of this copolymer was achieved in ethanol, a selective solvent for the PtBA block. The formed micelles consist of a PS core and a PtBA corona. Terpyridine ligands are located at the extremity of the PtBA chains and are available for complexation with metal ions. The effect of the addition of various metal ions to this system was studied in the dilute regime by dynamic light scattering. Whenever the concentration of the micelles is sufficiently low, addition of metal ions only results in the intramicellar complexation of terpyridine-ended PtBA coronal chains. Since terpyridine can either form mono-complexes or bis-complexes with metal ions, different situations have been observed depending on the metal-to-ligand ratio and on the nature of the metal ions. Finally, the possibility to use these metal–ligand complexes to add an additional poly(ethylene oxide) layer on the initial micelles has been demonstrated. This new approach opens a pathway to tune the size, conformation and functionality of coronal chains in block copolymer micelles.

Multicompartment micelles from a metallo-supramolecular tetrablock quatercopolymer

Multicompartment micelles with tunable compartment solubility have been prepared in alcohols from a metallo-supramolecular poly(p-tetrafluoromethylstyrene)-block-poly(tert-butylacrylate)-block-poly(styrene)-[Ru]-poly(ethylene glycol) tetrablock quaterpolymer.

Metallo-supramolecular materials based on amine-grafting onto polypentafluorostyrene

The post-modification of polypentafluorostyrene via the selective substitution of the para- fluorine by amine-functionalized molecules represents a versatile method for the preparation of functional materials. This communication presents the extension of this synthetic approach towards metallosupramolecular materials. First, the incorporation of terpyridines as metallo-supramolecular binding motifs is demonstrated, which enables the formation of a supramolecular crosslinked gel upon the addition of Fe(II) ions. Second, the linkage of phosphorescent iridium(III) complexes is reported yielding a copolymer that combines the excellent photophysical properties of the iridium(III) complex and the good solubility and processability of the polymer.

Combination of Different Chemical Surface Reactions for the Fabrication of Chemically Versatile Building Blocks onto Silicon Surfaces

The use of nucleophilic displacement reactions on bromine-terminated monolayers is presented to create new functional moieties onto silicon surfaces. Functional amines were used as suitable nucleophiles to introduce versatile building blocks onto self-assembled monolayers to perform further surface chemistry toward the fabrication of surfaces with designed properties by combining compatible chemical routes. These modified substrates were analyzed by suitable surface sensitive techniques. Furthermore, the functional monolayers were used for different postmodification reactions. For example, functional amines facilitated with acetylene groups were applied in the click chemistry approach. The use of amino-functionalized terpyridine units leads to the construction of supramolecular systems, where the choice of the metal monocomplex for the complexation is important for the tuning of the surface properties.