The recent advance of the aromaticity concept into the all-metal species enlightens us to explore whether all-metal aromatic system Al-4(2-) can adsorb small gas molecule on its surface. Y (Y = A(4)(2-), LiAl4- and Li2Al4) and X (X = H-2, N-2, O-2, F-2, Cl-2, Br-2, CO and SO) were chosen for this purpose. When interacting with X, the similarities and differences between all-metal aromatic system Al-4(2-)/LiAl4-/Li2Al4 and organic aromatic systems were discussed. Some special phenomena of Y... X induced by the characteristic of Al-4(2-) were investigated, which may give a base for the future research on the potential catalysis of these complexes. 2004 Elsevier B.V. All rights reserved.