Reactions of laser ablated lead atoms with oxygen molecules in condensing argon and nitrogen streams gave the PbO, OPbO, Pb(O-2), OPb(O-2), PbOPb, Pb2O2, PbPb(O-2), and Pb4O4 molecules. The formation of lead monoxide and Linear dioxide molecules is the main difference with thermal evaporation experiments. The linear OPbO isomer was identified from oxygen-18 and lead (natural abundance) isotopic substitution in the strong antisymmetric stretching absorption at 764.8 cm(-1); a weak v(1) + nu(3) combination band was observed at 1423.4 cm(-1). Two bands [nu(1) -728.7 cm(-1) (Ar) and 730.6 cm(-1) (N-2) and nu(2)=437.3 cm(-1) (Ar) and 449.6 cm(-1) (N-2)] are assigned to the cyclic isomer Pb(O-2) based on oxygen isotopic substitution. The position of the O-O stretching fundamental shows that Pb(O-2) is a peroxidelike molecule. The secondary reaction Pb(O-2)+Pb gives a large yield of cyclic Pb2O2 and allows observation of very strong antisymmetric Pb-O stretching fundamentals and combination bands with the two symmetric stretching fundamentals. Density functional frequency calculations with effective core potentials support assignment of the observed infrared absorptions.