Sahan R. Salpage

Area of research

Materials Chemistry · Physical and Theoretical Chemistry

Research interest

Research topics from publications: Examination of Structure and Bonding in 10-Coordinate Europium and Americium Terpyridyl Complexes; Creation of an unexpected plane of enhanced covalency in cerium(III) and berkelium(III) terpyridyl complexes; Conversion of Trivalent Uranium Anilido to Tetravalent Uranium Imido Species via Oxidative Deprotonation; Inhibited interlayer electron transfer in metal ion linked multilayers on mesoporous metal oxide films; Role of Metal Ion-Linked Multilayer Thickness and Substrate Porosity in Surface Loading, Diffusion, and Solar Energy Conversion; Influence of Dye-Coordinated Metal Ions on Electron Transfer Dynamics at Dye–Semiconductor Interfaces; Increasing excited state lifetimes of Cu(i) coordination complexes via strategic surface binding; Structural, electrochemical and photophysical properties of an exocyclic di-ruthenium complex and its application as a photosensitizer; Wavelength selective separation of metal ions using electroactive ligands. Representative work: M(TpyNO2)(NO3)3(H2O)·THF (M = La, Nd, Sm, Eu, Tb, Am; TpyNO2 = 4′-nitrophenyl terpyridyl) have been prepared from the reaction of M(NO3)3·nH2O with TpyNO2 in THF. Structural analysis shows that the metal centers are 10-coordinate, providing the first example of AmIII with this coordination number. Further spectroscopic and theoretical evaluation of these complexes reveals utilization of the 5f orbitals in bonding in the AmIII complex. Comparison of Nd–L, Eu–L, and Am–L bond distances demonstrates that some caution should be taken in comparing EuIII versus AmIII in extraction experiments Abstract Controlling the properties of heavy element complexes, such as those containing berkelium, is challenging because relativistic effects, spin-orbit and ligand-field splitting, and complex metal-ligand bonding, all dictate the final electronic states of the molecules. While the first two of these are currently beyond experimental control, covalent M‒L interactions could theoretically be boosted through the employment of chelators with large polarizabilities that substantially shift the electron density in the molecules. This theory is tested by ligating Bk III with 4’-(4-nitrophenyl)-2,2’:6’,2”-terpyridine (terpy*), a ligand with a large dipole. The resultant complex, Bk(terpy*)(NO 3