Luminescent species

Reisfeld R, Jorgensen CK (1991) Optical Properties of Colorants or Luminescent Species in Sol-Gel Glasses. 77 207-256... 

The key features of the EHI system are the monochromators and PUT assembly, since the former allow for minor variations In excitation or emission wavelength that may be necessary to differentiate lumophores of closely related structure, and the latter provides a means of quantitating luminescent species under study. Each monochromator has a resolution capability of 1 nm, and we anticipate that by careful selection of excitation and... 

Element Spectra Type Luminescing Species Excitation Range (nm)" Useful Emission Range (nm)"... 

Two practical advantages of luminescence species engulfed in antenna dendrimer scaffolds are apparent, namely their miscibility with organic media (solvents or/and resins) and their ability to form thin films. For example the lanthanide-cored dendrimer complexes described in this chapter can be regarded as organic-soluble inorganic luminescers. 

In dynamic quenching (or diffusional quenching) the quenching species and the potentially fluorescent molecule react during the lifetime of the excited state of the latter. The efficiency of dynamic quenching depends upon the viscosity of the solution, the lifetime of the excited state (x ) of the luminescent species, and the concentration of the quencher [Q], This is summarized in the Stern-Volmer equation ... 

Figure 9.24 Energy-level diagram for a luminescent species, in which a metastable state slows the rate of emission. The metastable state is also termed an ion trap...

We have discussed how to make highly luminescent species, but we have left unaddressed the more difficult question of how to incorporate specific sensitivity into molecular probes. There are two basic problems. First, one must develop a moiety with the desired specific sensitivity. Second, in doing so, one must not violate the basic criteria established earlier and inadvertently turn off the luminescence or introduce unacceptable photochemical sensitivity. 

Conversion of adsorbed light into emitted light of another wavelength occurs in any luminescent species. One would like, however, to perform separately the various steps of the overall process by means of different components that may be opti-... 

On dissolution of irradiated carbohydrates, a weak lyoluminescence is observed.381-308 The nature of the luminescent species has not yet been fully established. 

In summary the most likely explanation for dual emission with different lifetimes in d6 compounds is the presence of more than one luminescent species in the sample. 

Application of chemiluminescence to chemical analysis has been developing since the latter half of the 1950s. This method has many advantages, e.g., high sensitivity, good selectivity, linearity in a wide concentration range, and quick response. It has also been used for the measurement of air pollutants. This method, however, requires a supply of reactants to produce luminescent species through chemical reaction. This is a difficult point for the application of this method to gas sensors. 

The luminescent species that shows an emission peak at 420 nm is attributed to HCHO, but the origin of the other sub-bands has not yet been determined. Each amount of the generated luminescent species depends on the kind of combustible gas, so that the intensity of each emission sub-band is different from each other, and the profile of the overall spectrum is also different. This enables us to discriminate the kind of combustible gas from the profile of the CTL spectrum, ft should be noted, however, that the intensity ratio of the emission sub-band depends also on the ratio of combustible gas to oxygen and on the catalyst temperature [16,23]. 

In organic ECL reactions, the luminescent species are generally derivatives of polyaromatic hydrocarbons where A and B in Eqs. (1) through (4) can be either the same species (leading to self-annihilation) or two different PAHs with either being the analyte (mixed system). Some examples of both self-annihilation and mixed system ECL reactions of organic molecules are listed in Tables 1 and 2. One well-studied example is the self-annihilation reaction between the anion and cation radicals of 9,10-diphenylanthracene (DPA) via an S-route in acetonitrile resulting in blue fluorescence characteristic of DPA [17] ... 

In principle, the luminescent species relevant to this work are ... 

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