Pr Philip Andres

4′-Functionalized 2,2′:6′,2″-terpyridines as building blocks for supramolecular chemistry and nanoscience

Abstract Different mono- and bis-terpyridines were synthesized utilizing nucleophilic substitution of 4′-chloro-2,2′:6′,2″-terpyridine. In the case of the mono-functionalized ligands, different functional groups opposite to the metal binding site could be introduced; with the bis-functionalized ligands building blocks for metal-containing polymers with a tailored alkyl-chain length were accessible. As examples, a functionalized terpyridine cadmium(II) complex as well as a fullerene derivative were prepared.

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.

Metal ion assisted folding and supramolecular organization of a De Novo designed metalloprotein

This paper describes the supramolecular organization of a novel de novo designed metalloprotein, which consists of two N-terminal terpyridine modified coiled-coil protein folding motif sequences held together by an iron(II) ion. The self-assembly of the metalloprotein is the result of the interplay of metal ion complexation and protein folding, and can be manipulated by changes in concentration, temperature, and solvent. At low concentrations, folding and organization of the metalloprotein resembles that of the native coiled-coil peptide. Besides unimeric species, also dimeric and tetrameric metalloprotein assemblies were found. Several indications suggest that at least part of these unimeric species may exist as intramolecularly folded coiled-coils, however, unambiguous proof is lacking at the moment. At higher concentrations, folding and organization is dominated by the large octahedral [FeII(terpy)2] complexes (terpy = 2,2′:6′,2″-terpyridine) and considerable amounts of large, ill-defined aggregates are formed.