The addition reactions of germylenoid H2GeAlCl3 with ethylene: a theoretical investigation.

Theoretical calculations using the M062X and QCISD methods were performed on the addition reactions of the aluminum germylenoid H2GeAlCl3 with ethylene. The most two stable structures of germylenoid H2GeAlCl3, i.e., the p-complex and three-membered ring structures, respectively, were employed as reactants. The calculated results indicate that, for the p-complex, H2GeAlCl3 there are two pathways, I and II, of which path I involves just one transition state, while path II involves two transition states between reactants and products. Comparing the reaction barrier heights of path I (44.6 kJ mol-1) and II (37.6 kJ mol-1), the two pathways are competitive, with similar barriers under the same conditions, while for the three-membered ring structure, another two pathways, III and IV, also exist. Path III has one transition state; however, in path IV, two transition states exist. By comparing their barrier heights, path III (barrier height 39.2 kJ mol-1) could occur more easily than path IV (barrier height 92.8 kJ mol-1). Considering solvent effects on these addition reactions, the PCM model and CH2Cl2 solvent were used in calculations, and the calculated results demonstrate that CH2Cl2 solvent is unfavorable for the reactions, except for path II. In CH2Cl2 solvent, paths II and III are more favorable than paths I and IV.