Effects of Polymer Matrixes on the Time-Resolved Luminescence of a Ruthenium Complex Quenched by Oxygen

Abstract

Quenching of luminescence by oxygen of ruthenium diphenylphenanthroline in various polymers was studied by time-resolved spectroscopy. The luminescence decay was not single exponential, and the Stern-Volmer plot was nonlinear (downward-curved) in all cases. A new model for describing the nonexponential luminescence decay was developed, which considers the interaction of the fluorophore with the nonuniform environment provided by the polymer. This model has a better physical basis than the usual fits with multiple exponentials or lifetime distributions of arbitrary shape. Oxygen quenching is described by a single parameter, which, in favorable cases, depends linearly on oxygen pressure. This may be of advantage for the calibration of optical oxygen sensors based on luminescence quenching.

Characterization of excited electronic and vibronic states of platinum metal compounds with chelate ligands by highly frequency-resolved and time-resolved spectra

“…More recently, within the last one or two decades, it has become apparent that these complexes exhibit an enormous potential for new applications due to their photophysical and photochemical properties. For example, systems involving photo-redox processes for solar energy conversion [4][5][6][7][8][9][10][11], photovoltaic devices [12,13], molecular photodiodes [14] or chemical synthesis [15], information storage systems [16], highly sensitive chemical sensors [17,18] and biosensors [ 19 -22], low-dimensional semiconductors with extreme tunabilities of optical transitions under high pressure [23,24], and supramolecular systems with user-defined photophysical properties [25,26] have already been explored or are under current investigation. All of these properties and possible applications are related to the characteristics of the lowest excited states.…”

Indicators for optical oxygen sensors

“…Examples are sol-gel [147,152,154,249], ethyl cellulose or PVC membranes [61], different types of ORMOSILs [39,94,106], polystyrene [91], polysulfones [11,18], poly (dimethylsiloxane) alone [251] or with different amounts of pendant acrylate groups [168], and a blended fluoropolymer matrix consisting of Nafion ® and Aflas ® [83]. In another approach, the [Ru(dpp) 3 ] 2+ complex was adsorbed onto silica and then dispersed in a silicone rubber support [38,93].…”

Luminescent Chemical and Physical Sensors Based on Lanthanide Complexes

“…Immobilization or incorporartion into polymer matrices does usually not affect the spectral characteristics or the lifetime of a luminescent probe. But its encapsulation can significantly change the response characteristics to a given analyte [75]. Ideally, the sensitivity and selectivity of the luminescent probe can be increased by choosing an appropriate matrix.…”