Group theoretical predictions, transition metal

The experimental techniques that have been used to study transition metal atom reactions (crossed molecular beams, flow tubes, etc.) are powerful ones. However, a complete interpretation of the mechanistic and dynamic aspects of these reactions is greatly facilitated through comparison of experimental results to theoretical predictions.159 The early theoretical work by the group of Siegbahn led to a great number of testable predictions, many of which have been found to be remarkably precise. Our measurements of various thermodynamic quantities have shown these calculations to be generally accurate to within 5-6kcal/mol. Unfortunately, due to the... 

In 1937 Jahn and Teller applied group-theoretical methods to derive a remarkable theorem nonlinear molecules in orbitally degenerate states are intrinsically unstable with respect to distortions that lower the symmetry and remove the orbital degeneracy.37 Although Jahn-Teller theory can predict neither the degree of distortion nor the final symmetry, it is widely applied in transition-metal chemistry to rationalize observed distortions from an expected high-symmetry structure.38 In this section we briefly illustrate the application of Jahn-Teller theory and describe how a localized-bond viewpoint can provide a complementary alternative picture of transition-metal coordination geometries. 

Another area where significant work has been done is in the prediction of activation barriers of chemical reactions. Truhlar and co-workers have assembled a set of 44 barrier heights [65] for assessment of the performance of theoretical methods for thermochemical kinetics . Finally, a hmited set of thermochemical information has been collected for molecules containing third-row main group elements and for transition metal systems [27-29,73,74]. 

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