Luminescent Osmium Polypyridyl Complexes
Elise G. Megehee, Department of Chemistry, St. John’s College of Liberal Arts and Sciences
Irma Tertulien, Pantea Menhaji, and Joseph Capritto, St. John’s College student
Osmium metal complexes are of interest as they exhibit visible luminescence upon excitation with visible or ultraviolet light. These compounds are of interest as possible as models of photosynthetic reaction center, as energy and electron transfer agents, and as photochemical or electrochemical reaction catalysts. We have undertaken a series of studies to determine the versatility of bis-(2,2'-bipyridine)-carbonyl-(triflato)osmium(II) as precursor to new luminescent osmium complexes. Our syntheses have been divided into four areas: 1) Alkyl complexes whose syntheses give two structural isomers with very different chemical and physical properties. 2) Osmium triflato intermediate made with other dinitrogen ligands to show the versatility of this synthetic method. 3) Pyridine complexes of the various osmium triflato precursors to determine the effect of various electron donating and electron withdrawing groups on the dinitrogen ligand and to serve as model complexes of our osmium-porphyrin dyad work. 4) Phosphine complexes using neutral phosphine ligands in order to determine how various electron donating and electron withdrawing groups attached to the phosphine affect the physical properties of the osmium complex.