Artificial Tripeptide Scaffolds for Self-Assembly of Heteromultimetallic Structures with Tunable Electronic and Magnetic Properties

Abstract

An artificial tripeptide containing pendant pyridine and bipyridine ligands has been synthesized using a solution-phase method analogous to divergent dendrimer synthesis, yielding a palindromic multifunctional peptide chain. When compared to conventional solid-phase peptide synthesis, this method rapidly yields the tripeptide in significantly greater quantities. The pendant pyridine ligands are coordinated with stoichiometric quantities of either [Pt(tpy)] 2+ or [Cu(pda)] metal complexes. By addition of a second transition-metal ion, supramolecular structures are formed by chelation of the bipyridine ligands to create cross-links between oligopeptide strands. The resulting heteromultimetallic materials have unique optical, electrochemical, and magnetic properties that can be tuned by the choice of transition-metal ions.

Square-Planar Pd(II), Pt(II), and Au(III) Terpyridine Complexes: Their Syntheses, Physical Properties, Supramolecular Constructs, and Biomedical Activities

“…172 Complex 238 displayed two distinct absorptions at ca. 340 and 537 nm, which were attributed to Pt-tpy and Fe-tpy MLCT bands.…”

“…171,172 It was assumed that the four-tethered Pt-terpyridine complexes on the backbone of the peptide chain, as in 234, which resemble nucleic acids on the DNA sugar-phosphate backbone, would increase binding affinity of 234. To this extent, a doublestranded (ds) DNA fragment with 12 base pairs (bp) was chosen as a model for binding studies (Figure 102).…”

Synthesis and Characterization of a (Dipyridylthiophene)platin Complex of a Pyridyl‐Substituted Aminoethylglycine Artificial Dipeptide

“…We have previously described the synthesis and characterization of artificial oligopeptides with an aminoethylglycine (aeg) backbone that contain heterocyclic pendant ligands 2,5. These compounds rely on metal coordination to form the single‐stranded,2a,2b duplex,2a,2c,2d and hairpin5 geometries shown in Scheme . These structures self‐assemble on the basis of the denticity of the attached ligand and coordination chemistry of the added metal ions.…”

Modulation of the conductance of a 2,2′-bipyridine-functionalized peptidic ion channel by Ni2+

“…Here, we attached a bipyridine moiety to the N-terminus of this peptide. Bipyridine is a well-characterized metal acceptor, which is utilized for various supramolecular assemblies including α-helical coiled coil peptides (Gilmartin et al 2005 ; Kaes et al 2000 ; Koide et al 2002 ). Several examples are found in literature, where water soluble peptides are covalently coupled to 2,2′-bipyridine allowing complex formation via metal cations resulting in dimeric and trimeric peptide assemblies (Ghadiri et al 1992 ; Gochin et al 2002 , 2003 ; Liebermann and Sasaki 1991 ).…”