The SO2 complexes of scandium, yttrium, and lanthanum difluorides [MF2(O2S)] were prepared via the reactions of laser -ablated metal atoms and SO2F2 upon UV-vis irradiation in cryogenic matrixes. The presence of bidentate SO2 ligand in the products was demonstrated by the characteristic infrared absorptions as well as isotopic frequency ratios from both (SO2F2)-O-18 and (SO2F2)-S-34 experiments and is further supported by DFT calculations. All three product molecules were predicted to have nonplanar C-2v, symmetry with the SO2 ligand bound to the metal center through both oxygens. The computed S-O bond length and stretching frequencies of ligated SO2 approach those of SO2- as a result of electron transfer from metal center to the 1 pi* orbital of SO2, in agreement with the results from bonding analysis. On the basis of DFT calculations, fluorine transfer from SO2F2 to the metal center to form the MF2(O2S) complexes is highly exothermic. Although a proposed intermediate in the form of MF(O2SF) was predicted to be stable, it was not observed in the experiments, presumably because of the low energy barrier for further isomerization to MF2(O2S).