Absolute value of bond dissociation energy as a reaction direction marker.

The calculation problem of bond-dissociation energy D0(M+-S) for M = Sc, Ti, V, Y, Zr, Nb was solved using the fundamental law of nature determining the dependence of chemical bond dissociation energy on its length. The recommended experimental values from literature are as follows D0(Sc+-S)=4.97±0.05 eV, D0(Ti+-S)=4.74±0.07 eV, D0(V+-S)=3.78±0.10 eV, D0(Y+-S)=5.49±0.18 eV, D0(Zr+-S)=5.69±0.10 eV, D0(Nb+-S)=5.20±0.21 eV. The theoretical data calculated in this article are 4.967 eV, 4.72 eV, 3.772 eV, 5.505 eV, 5.694 eV, 5.209 eV correspondingly which is in good agreement with the literature. Besides the recommended D0(M+-S) values, there are more data referring to D0(M+-S) in reactions of transition metal sulfides (M = Sc, Ti, V, Y, Zr, Nb) with oxygen-bearing substrates such as COS, CO, and CO2. It should be noted that different directions of the reaction corresponded to different observed values of bond dissociation energies (M+-S). The experimental D0 values for metal sulfide species from literature were calculated with high accuracy. In our calculations, we used the bond lengths from the literature calculated for various electronic configurations. Therefore, we assume that the previously obtained data allow us to define correlation between reagent electronic state and corresponding reaction direction.