Ben A Degraff

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Oxygen quenching of a series of Os(II) complexes with α-diimine ligands has been studied in a predominantly poly(dimethylsiloxane) (PDMS) polymer and in Gp-163 (an acrylate modified PDMS). Unlike previous Ru(II) complexes used as oxygen sensors, the Os complexes can be excited by readily available, high-intensity, low-cost, red diode lasers at 635, 650, and(More)
The rapid lifetime method (RLD) for determining excited-state lifetimes uses the ratio of the areas under two regions of the decay. To get good precision with the standard method, prior knowledge of the lifetime is essential to selecting the integration regions. As will be shown, the usual method of selecting integration regions is far from optimal. An(More)
A rapid and reproducible method for determining the temperature dependence of luminescence lifetimes has been developed. With the use of this method, a set of standards for the excited-state lifetime oxygen quenching of several ruthenium(II) transition metal complexes was established. With the use of three solvents of different viscosities and two metal(More)
Oxygen quenching of [Ru(Ph2phen)3]Cl2 (Ph2phen = 4,7-diphenyl-1,10-phenanthroline) has been studied in a diverse series of polymers, most with a common poly-(dimethylsiloxane) (PDMS) component. Systematic variations in the polymer properties have been made in order to delineate the structural features important for satisfactory use of supports for oxygen(More)
For evaluating exponential luminescence decays, there are a variety of computational rapid integral methods based on the areas of the decay under different binned intervals. Using both Monte Carlo methods and experimental photon counting data, we compare the standard rapid lifetime determination method (SRLD), optimized rapid lifetime determination methods(More)
The effects of oxygen on the photochemical properties of ruthenium(II) complexes in solution and in polymers are reported. In solution, the complex is actually protected from decomposition by the presence of oxygen as a result of deactivation of the complex by oxygen quenching before it can undergo ligand loss by monomolecular dissociation; however, in(More)
Oxygen quenching of pyrene has been studied in a diverse series of polymers. Most measurements were made using homo- or copolymers containing a poly(dimethylsiloxane) region. Systematic variations in the polymer properties have been made in order to delineate the structural features important for satisfactory use as supports for oxygen sensors. In(More)
Luminescence quenching of Ru(II) complexes by oxygen has proved a powerful method of quantitative oxygen analysis. It has become clear that the polymer support for the sensor molecule plays a pivotal role in the sensor performance. The current work is devoted to understanding how the physical and photophysical properties of a sensor respond to changes in(More)
A new class of luminescent rhenium complexes has been tested as oxygen sensors based on luminescent quenching. ReL(CO)3Cl and ReL(CO)3CN (L = 2,2′-bipyridine or 1,10-phenanthroline and substituted analogues) have several features that seem to indicate suitability as oxygen sensors. These include simple synthesis, long excited-state lifetimes, and high(More)