Abstract: The potential energy surfaces for the abstraction reaction of germylene with thiirane have been char-acterized in detail using density functional theory (DFT). All the stationary points were determined at the B3LYP/6-311++G (d, p) level of the theory. The transition states both to the reactants and the product direction in the reaction paths were examined by using the intrinsic reaction coordinate (IRC). The major conclusion is as follows: the reaction is in two steps, (1) germylenes and thiirane form an intermediate complex through an exothermal reaction without any barrier; (2) the intermediate complexes isomerize to give the products. Furthermore, the stronger the π-donation is or the more electronegative the substituents are the bigger the ΔEST of X2Ge, the higher the activation energy for the abstraction reactions will be. In other words, it is the electronic factors, rather than the steric factors, that play a decisive role in the chemistry of the germylene species. A configuration mixing model based on the work of Pross and Shaik is used to rationalize the computational results.

Key words: Germylene, Thiirane, DFT, Configuration mixing model