Poster abstracts
Poster number 17 submitted by Austin Lanquist
Investigation of Ligand Electronic Effects on the Photodissociation of Acetonitrile from Ruthenium Polypyridyl Complexes
Austin Lanquist (OSU )
Abstract:
A series of five ruthenium polypyridyl complexes Ru(bpy)2P(PhR)3(CH3CN)]2+ triphenylphosphine derivative (R = OCH3, Me, H, F, CF3) have been synthesized and characterized in order to better understand the effect of changing electronic character has on the photodissociation of acetonitrile. Methods of characterization include 1H and 31P NMR, ESI-MS, cyclic voltammetry, fluorescence, and single crystal X-ray diffraction. Photolysis of this series exhibited a clean transition from reagent to photoproduct for all five complexes. Ru(bpy)2P(PhOMe)3(CH3CN)]2+ proved to be the most efficient at photosubsitution with a measured Ф400 of 0.76, exhibiting a 3-fold increase when compared to that of the weakest in the series, Ru(bpy)2P(PhCF3)(CH3CN)]2+ with a Ф400 of 0.26. Quantum yields were then compared with properties such as Hammett para substituents, phosphine pKa values, 31P-NMR signal, and HOMO-LUMO gap and found to trend exceedingly well. Discoveries herin prove that more effective photodynamic therapy reagents (PCT) can be synthesized by the addition of more electronic donating substituents.
Keywords: Ruthenium , Photochemotherapy , drug release