Intensity diagrams

Fig. 5.37. Schematic intensity diagram for some different types of reaction. The fluorescent molecules will fluoresce at both wavelengths the intensity diagram is plotted,...

Fig. 5.38. Schematic intensity diagrams for a specific sequence of reaction products. By variation of the wavelength of observation the various spectral fluorescence distributions will vary. This influences the form of the intensity di am obtained.

Fig. 5.39. Intensity diagram of the photoreaction of anthrone-anthranol in methanol irradiated at 313 nm and synchronised to equal times of measurement [175].

Fig. 5.40, Intensity diagram of the photodegradation of CPTC in methanol, irradiated at...

Even in the case of a uniform reaction sometimes some curvatures instead of straight lines are found in intensity diagrams. This problem arises if the absorbance at the wavelength of the irradiation exceeds 0.02 units. The influence is shown in Fig. 5.41. 

Fig. 5,41. Calculated intensity diagrams for the reaction dependent on the change in...

For the consecutive reactions intensity diagrams are curved if besides another reactant also fluoresces. Examples are given for laser dyes (see Fig. 5.43) [92,93] and for short wavelength irradiation of anthrone [180]. In the case of CPTC at irradiation by 254 nm even an intensity quotient diagram can be constructed (see Fig. 5.44). These diagrams correlate with those of extinction difference quotient diagrams (see Section 5.3.3.1). 

In the case of the photoreactions of anthrone and anthraquinone only the intensity diagrams were used to support mechanistic considerations obtained by formal kinetic examinations using absorbance. However, in the process of the examination of the photostability of laser dyes, quantum yields have been determined applying the equations given in Sections 5.5.1 and 5,5.1.1. 

Figure 33-1. Temperature dependence of the position of the main peak in the X-ray scattering intensity diagram (above) and the viscosity in Pa s (below) for sulfur.

Such emissions, often located in the spectra close to intense diagram lines are also called satellites. 

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