Thermochemistry of Arene Complexes

Thermochemical data for arene complexes are less abundant than for metallocenes. This is due in part to incomplete combustion of the compounds. The energies of dissociation of metal-arene bonds were obtained from mass spectra for most of the complexes. However, data obtained by this method are somewhat higher (by ca lOOkJmol and even higher). In some cases, even the reverse order of the relative stabilities for a given series of compounds is obtained. Table 10.8 gives energies of dissociation of metal-arene bonds which are obtained by calorimetric methods. 

The dipositive ion undergoes unusual decomposition to singly charged ions in the metastable transition  

Analogous reaction is observed for vanadium compounds [V(PhH)2]. The band intensity of the ion changes due to thermal decomposition, which is temperature 

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