Date of Graduation

Summer 2016

Degree

Master of Science in Chemistry

Department

Chemistry and Biochemistry

Committee Chair

Mark Richter

Abstract

The photoluminescent (PL), electrochemical, and electrogenerated chemiluminescent (ECL) properties of 1,5-I-Aedans (N-(iodoacetylaminotheyl)-1-naphthylamine-5-sulfonic acid) in aqueous buffered (KH2PO4) and 50:50 (v/v) acetonitrile:KH2PO4 solutions were obtained. Tri-n-propylamine (TPrA) was used as the oxidative-reductive coreactant. The PL efficiencies (em) were 1.83 in KH2PO4 and 4.81 in mixed solvent compared to Ru(bpy)32+ standard solutions (em = 1.0). 1,5-I-Aedans displayed quasi-reversible oxidative electrochemistry in aqueous solutions and irreversible to quasi-reversible oxidation in mixed solvent. ECL efficiencies (ecl) were obtained by comparison to a Ru(bpy)32+/TPrA (bpy = 2,2'-bipyridine) standard (ecl = 1) and were higher in KH2PO4 (ecl = 6.8 x 10-4) than in the mixed solvent system (ecl = 0.072 x 10-4). A second project studied the ECL of the Ru(bpy)32+/TPrA system when melatonin (N-acetyl-5-methoxytryptamine; MLT) is present in aqueous buffered solution. MLT displays weak ECL when TPrA is used as the oxidative-reductive coreactant, but when micromolar concentrations of MLT were added to the system, up to 2.5-fold enhancement was seen. PL efficiencies did not change in the presence of MLT unless the solution underwent electrochemical bulk oxidation. Spectroscopic, electrochemical and spectro-electrochemical studies indicate that the mechanism involves oxygen scavenging by MLT oxidation products. This scavenging prevents quenching of the *Ru(bpy)32+ excited states.

Keywords

enhanced electrogenerated chemiluminescence (ECL), coreactants, melatonin, 1, 5-I-Aedans, Ru(bpy)32+

Subject Categories

Chemistry

Copyright

© Sarah Michelle Roughton

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