2008 Volume 49 Issue 11 Pages 2429-2436
This work demonstrates that the binding of Li atom plays an important role in the Al4Li4 clusters, which changes the structure of the Al4 ring and induces the distinct magnetic shielding properties depending on the position of Li atom. The Al4Li4 cluster possesses both aromatic (S type) and antiaromatic (L type) isomers depending on the position of Li atom with an 8.74 kcal/mol energy difference at the singlet state. The bond length alternation (BLA) values and nucleus independent chemical shift analysis of each canonical molecular orbital (NICS-CMO) analyses show that S type isomers are aromatic and L type isomers are antiaromatic as the singlet low-lying states. A cyclic reaction pathway between L and S type isomers is mapped with five low-lying and five transition states including two intermediate states.