THERMODYNAMIC STABILITIES OF YLIDES AND T HEIR CORRESPONDING RADICALS

Determinations of the equilibrium acidities in dimethylsulfoxide solut ion and the alpha-C-H homolytic bond dissociation energies in the gas phase for structurally different triphenylarsonium, tributylphosphoniu m and dibutyltellurium ylide precusors are reported. The thermodynamic stabilities of the corresponding carbanions and carbon radicals as we ll as the nature of the P-C bonds in phosphonium ylides and its influe nce on the properties of the ylides are discussed in detailes, based o n a comparison with other type of ylides of the similar structure and on the structure - property relationship.