Abstract: The geometries and insertion reactions of germylene H2GeLiF with R–H (R=F, OH, NH2) have been investigated at the B3LYP/6-311+G level of theory. The potential barriers of the three reactions are 95.18, 156.91, and 211.41kJ/mol, respectively. Here, all the mechanisms of the three reactions are identical to each other, i.e. an intermediate has been located during the insertion reaction. The intermediate could dissociate to substituted germylane and LiF with a barrierless process. Correspondingly, the reaction free energies for the three reactions are −75.71, −34.27, and −8.48kJ/mol, respectively. Compared with the reactions in the unsubstituted cases, the reaction activities of those insertion reactions of GeH2 should be increased upon complexation of LiF. [Copyright &y& Elsevier]