Kenyon College	HHMI Grants to Kenyon	Howard Hughes Medical Institute

CHEM 372 Advanced Lab - Inorganic

Fluorimeter
Nanoscience Chemistry
Advanced Inorganic Lab
Bacterial Fluorescent Protein

Phosphorescence quenching of *[Ru(bpy)3]2+ (2.0 x 10-5 M) by Q = pyrene having concentrations of: (1) 0 M, (2) 4.6 x 10-4 M, (3) 9.2 x 10-4 M, (4) 1.4 x 10-3 M, (5) 1.8 x 10-3 M,

Stern-Volmer plot of quenching data using from both luminescence intensity (quantum yield, f) measurements and lifetime (t) measurements. Student data show excellent agreement between the two methods.

Students investigate the rate of energy transfer reactions between the excited-state metal complex *[Ru(bpy)₃]²⁺ and aromatic energy-acceptor quenchers (Q) such as anthracene and pyrene. Quantum yield (φ) data obtained using the Fluorolog-3 spectrophotometer are compared to quenching data obtained using a laser lifetime system (NSF grant). Using a Stern-Volmer (SV) kinetics analysis, rate constants on the order of 10⁹ M^-1 s^-1 are calculated, and the relationship between rate constants and thermodynamic driving force (ΔG) investigated.