High-energy emissions

Lanthanide ions have been used as DEFRET acceptors in split probes for DNA sequence such as shown in Figure 15.137 When using europium and terbium complexes, the choice of chromo-phores is rather restricted, owing to the high-energy emissive states associated with these ions (vide supra). In this case, the donor chromophore is a salicylic acid unit appended to an... 

One useful, high-energy emission from excited electrons is the X-ray. What is the wavelength (in meters) of an X-ray with a frequency of v = 8.72x10 Hz ... 

Based on lifetime measurements, the authors also propose that the high energy emission is fluorescent and the low energy one is phosphorescent, the latter being strongly influenced by the close proximity of the gold centers of different molecules because it disappears completely when there are no intermolecular interactions. 

While Thomson and others were busy studying electrical phenomena, Henri Becquerel discovered a new phenomenon—radiation. (We will discuss radiation in more detail in Chapter 5.) The study of this new type of high-energy emission from materials was the principal focus of Ernest Rutherford. Rutherford s initial work discovered two new types of particles associated with the high-energy emissions, the alpha (a) particle and the beta ((3). These are now known to be a helium nucleus and an electron, respectively (more on this in Chapter 5). 

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