Stability relative to isomeric structures

For example, based on equation 24, it can be concluded that the isomerization reaction of H2M=CH2 to HMCH3 becomes more exothermic as M becomes heavier, due to the decrease in the M—H bond dissociation energy (Table 3) and in D , and the increase in the DSSE of the MH2 fragments. This conclusion is supported by ab initio calculations. For example, equation 24 leads to predicted isomerization energies of H2M=CH2, M=Si and Ge of 5.8 and —15.3 kcal mol 1, respectively, in good agreement with the ab initio calculated values of 4295 and —15296 kcal mol-1, respectively. 

6 At the G1 level from Reference 298. For older (usually lower level) values, see Reference 7. At MP3/6-31G(d,p)//HF/6-31G(d) from Reference 299. 

4 At various CISD and CCSD levels from Reference 296. 

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