Synthesis and characterization of a (dipyridylthiophene)platin complex of a pyridyl-substituted aminoethylglycine artificial dipeptide

We report the solution-phase synthesis and characterization of an artificial pyridyl-substituted dipeptide that is crosslinked by a 2,5-bis(2-pyridyl)thiophene (dpt) platinum complex. The small molecule equivalent for the Pt(dpt)dipyridyl-peptide is synthesized for comparison. These compounds are characterized by two-dimensional and variable-temperature NMR, mass spectrometry, electrochemistry, UV/Vis absorbance and emission spectroscopy, and their photo-emission dynamics are compared. The complexes have two reversible, ligand-centered reductions, are luminescent at room temperature, and have two distinct radiative relaxations with nanosecond and microsecond lifetimes. These metallated peptide building blocks are promising for use as stable inorganic complexes to label synthetic peptides with luminescent and redox-active probes.