The electronic properties of carbenes including thermodynamic parameters such as new electronic philicity indices Ie, Ph, and for comparizon chemical hardnesses η, proton affinities (РA) calculated by DFT method (B3LYP5/6-31G*/RHF for definition of electronic indices and B3LYP5/3-21G/RHF, B3LYP5/3-21G/UHF for definition of chemical hard¬nesses) have been discussed in the paper. With their help, the estimation of philicities, electron-donating and electron-withdrawing abilities of a wide range of carbenes of both nucleophilic and electrophilic type was carried out. It was established that the philicities of carbenes according to electronic indices Іе, Ph depend on the carbenic structure (the backbone of the molecule and steric effects of substituents) and also on the reagent structure, particularly its steric effect. For typical nucleophilic carbenes, the Ph is in the range of 1–3,0, for neutral carbenes 1–1,5, IeH 8,5–22,2 eV, for neutral carbenes IeH 8,5–10,5, for typical electrophilic – in the intervals of PhH –0,3–0,5, IeH –3,4–3,4 eV. The intermediate values (Ph 0,5–1,0, IeH 3,4–8,5 eV) are characteristic for typical ambiphilic carbenes. In the evaluation of electron-donating a
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