Quantum chemical studies of propene, ethylene, acetylene and dihydrogen reactivity in the insertion reaction into the titanium-alkyl bond

Using the ab initio method of SCF MO LCAO SCF MO LCAO: Self‐consistent field molecular orbital linear combination of atomic orbitals. in a valency‐splitted basis of the Gaussian functions we have studied the addition of various monomers (C3H8, C2H4, C2H2) and dihydrogen to the titanium‐alkyl bond in the complex H2TiCH3. The structure of transition states in the insertion reaction, heats of π‐complex formation and activation energies for the insertion of the coordinated monomers have been calculated. The calculation results show that the reactivity decreases in the order C2H2 > C2H4 > C3H8 > H2. According to the results obtained, the energy of the π*‐antibonding orbital of monomers can serve as an index of relative reactivity in the insertion reaction into the metal‐alkyl bond.