Cyclic Pb(SO2), Pb(SO2)2 and Pb2(SO2) molecules: Matrix infrared spectra and DFT calculations

Reactions of laser-ablated lead atoms with SO2 in excess argon produced three new molecules, cyclic Pb(SO2), Pb2(SO2) and Pb(SO2)2, all with η2-O,O bonded structure, which were identified by 34SO2 and S18O2 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.