H Harald Hofmeier

Recent developments in the supramolecular chemistry of terpyridine-metal complexes

This critical review describes recent developments in the field of supramolecular chemistry of terpyridine-metal complexes. The synthesis and characteristics of single as well as multiple homo- and heterometallic complexes is discussed. Furthermore, complexes containing fullerenes, biological building blocks, extended aggregates of different architectures as well as rings are presented. A special emphasis is placed upon the properties (e.g. redox properties, luminescence etc.) of functional systems. Potential applications in optical nano-devices, molecular storage units, molecular switches and solar cells are discussed.

Metallo-Supramolecular Graft Copolymers: A Novel Approach Toward Polymer-Analogous Reactions

A copolymer of poly(methyl methacrylate) with terpyridine units in the side chains was synthesized utilizing free-radical polymerization. The free terpyridine units were complexed with several different terpyridineruthenium mono-complexes, yielding metallo-supramolecular graft copolymers. The materials obtained were characterized by means of NMR and UV-vis spectroscopy as well as GPC. Characterization by thermal analysis revealed distinct differences between these new materials and the initial copolymer.

New supramolecular polymers containing both terpyridine metal complexes and quadruple hydrogen bonding unitsElectronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b3/b314459n/

Molecules containing quadruple hydrogen-bonding units as well as metal-complexing terpyridine moieties have been designed and assembled to result in a supramolecular polymer where both interactions are present in the main chain.

Terpyridine-ruthenium complexes as building blocks for new metallo-supramolecular architectures

Supramolecular architectures are of great interest in modern materials research. The directed synthesis of asym-metric 2,2′:6′,2′′-terpyridine ruthenium(II) complexes is an important tool towards such systems. In this contribution, we report the synthesis of asymmetric terpyridine ruthenium(II) complexes as models for supramolecular architectures and polymers. Terpyridines, bearing different functional groups in the 4′-position, were complexed with unfunctionalized terpyridine ligands using Ru(III)/Ru(II) chemistry. The resulting compounds were characterized by UV-vis, one- and two-dimensional NMR spectroscopy as well as MALDI-TOF mass spectrometry. In addition, X-ray structure analysis was performed for one selected example.

Linear coordination polymers: synthetic strategies and solution viscosities

Different synthetic strategies for the preparation of the coordination polymers [bis (2,2′:6′, 2′′-terpyridin-4′-yl)-FeCl2-di(ethylene glycol)]n, [bis (2,2′:6′,2′′-terpyridin-4′-yl)-Ru(BF4)2-di(ethyle glycol)]n, [bis (2,2′:6′,2′′-terpyrid-4′-yl)-FeCl2-poly(ethylene glycol)180]n and [bis (2,2′:6′,2′′terpyrid-4′-yl)-Ru(BF4)2-poly(ethylen glycol)180]n are reported. The influence of solvent, concentration and mode of metal ion addition is discussed on the basis of the observed solution viscosities.

First GPC results of terpyridine based chain extended supramolecular polymers: comparison with viscosity and analytical ultracentrifugation

Abstract The molecular weight of an extended metallo-supramolecular polymer, based on a α,ω-bis-terpyridine-poly(ethylene glycol) polymer linked via ruthenium(II) ions, was determined by gel permeation chromatography, viscosimetry as well as analytical ultracentrifugation. An optimized GPC method was applied for the first time to this kind of chain extended supramolecular polymers and the obtained results showed a good agreement with viscosimetry and analytical ultracentrifugation. A chain extended polymer with an average molecular weight of around 140 000 was found. These results clearly demonstrate that well-soluble high-molecular-weight metal-containing coordination polymers that are based on well-defined telechelics can be synthesized and fully characterized.

Combination of supramolecular cross-linking with covalent cross-linking through epoxide ring-opening including gel studies

Abstract Terpolymers based on poly(methyl methacrylate), containing terpyridinemoieties as well as epoxide groups, were synthesized via free-radical polymerization. The products were cross-linked non-covalently with iron(II) ions and covalently by treatment with AlCl3. Both steps could be combined in different order. The non-covalent cross-linking could be reversed by applying a strong competing ligand. The swelling behaviour of the polymers was investigated.