Reactions of laser-ablated lead atoms with SO2 in excess argon produced three new molecules, cyclic Pb(SO2), Pb-2(SO2) and Pb(SO2)(2), all with eta(2)-O,O bonded structure, which were identified by (SO2)-S-34 and (SO2)-O-18 isotopic substitutions. The observed infrared spectra and molecular structures of three molecules were confirmed by density functional theoretical calculations. Mulliken and natural charge distributions indicate significant electron transfer from d orbitals of lead metal to SO2 ligand and lead-oxygen bond exhibits strong polarized covalent character. (C) 2013 Elsevier B.V. All rights reserved.