Thayer-Yardley plot

Fig. 1. Cross-section for collision-induced intersystem crossing in glyoxal presented in a Thayer-Yardley plot." Figure taken from Beyer and Lineberger. Symbols defined following Eq. (1.3). Note that CHjCl and CH3CN have large quadrupole moments and Oj has a magnetic moment which are not included in the Thayer-Yardley correlation.

A plot of Oq vs the Thayer-Yardley parameter is shown in Fig. 9 for the A(v= 1) state. A clear trend emerges from the figure—lending support to the validity of nonresonant energy transfer. A difficulty arises, however, on trying to estimate absolute values according to the model. Equation (24) may be used to calculate the quenching cross-sections for the A(v=0) or A(v=l) states. The process may be written as... 

In this case, the term cjr includes the dispersion force and higher moment interaction and the capturing cross section will be proportional to This again provides a way to correlate the experimental data of the collision-induced ISC cross section against the physical properties of S and A. [Other types of plots have been proposed by Rossler (1935), Selwyn and Steinfeld (1969), Thayer and Yardley (1972, 1974) and Parmenter (1974).] None of the proposed plots can be expected to meaningfully correlate all the observed data of collision-induced ISC. This is partly because the complex formation may not be fully described by the simple form of V r) given by Eq. (117). Furthermore, P E) may not be completely independent of the physical properties of quenchers. 

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