Stem-Vohner plots

The intense and long-lived luminescence of these complexes has been utilized in the development of the oxygen sensor. Four mononuclear and dinuclear cyclometalated iridium(III) diimine complexes were immobilized in polymerized poly(ethylene glycol) ethyl ether methacrylate matrices, and the oxygen quenching on the luminescence of the films was studied. Tinear Stem-Vohner plots were obtained. Despite the difference in the luminescence energy and lifetimes of the complexes, similar Stem-Volmer slopes were observed. The size and charge of the complexes played an important role in the sensitivity of the systems. 

Fig. 16 Stem-Vohner plots for the quenching of the luminescence of [Eu2(L )3] by aciidme orange (left) and ethidium bromide (right) in Tris-HCl buffer (pH 7.4). Open squares lifetimes, solid squares intensities. Redrawn after [47]...

Figure 15 Stem-Vohner plot of luminescence intensity and lifetime quenching of [Ru(dpp)3] + by the closed form of BTF6 in degassed acetonitrile solution. Data taken from Figure 14. (Adapted with permission from Ref. 45. American Chemical Society, 2004.)...

Figure 3.17 shows the corresponding Stem-Volmer plot obtained for energy transfer from the lowest energy singlet state of naphthalene = 385 kJ mor ) to biacetyl ( si = 267 kJ mor ) [18]. From the slope of the Stem-Vohner plot the product kg Q = 268 M is obtained, from which, using the experimental fluorescence lifetime Tq = 18.2 nsec... 

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