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We experimentally investigate the ultrafast photodissociation dynamics of the SO 2 molecule induced by intense ultrashort laser pulses in a pump-probe scheme. Different three-body fragmentation pathways are discriminated using the time-dependent kinetic energy release spectrum with femtosecond time resolution. A nontrivial three-body fragmentation pathway, denoted as the bonding pathway, is unraveled, in which an intermediate fast rotating O 2 molecule is formed before complete fragmentation. The ultrafast chemical bond rearrangement after electron release is tracked in real time. The bonding pathway generally exists in the three-body fragmentation processes induced by strong laser fields of different wavelengths, which is observed in infrared, ultraviolet, and mixed two-color cases. Our findings are significant for understanding the photon-induced ultrafast processes of the SO 2 molecule in atmospheric chemistry.

Sodium superionic conductors are keys to develop high safety and low cost all-solid-state sodium batteries. Among developed sodium ionic conductors, antiperovskite-type ionic conductors have attracted vast interest due to their high structural tolerance and good formability. Herein, we successfully synthesize Na 3 OBH 4 with cubic antiperovskite structure by solid-state reaction from Na 2 O and NaBH 4 . Na 3 OBH 4 exhibits ionic conductivity of 4.4 × 10 -3 S cm -1 at room temperature (1.1 × 10 -2 S cm -1 at 328 K) and activation energy of 0.25 eV. The ionic conductivity is 4 orders of magnitude higher than the existing antiperovskite Na 3 OX (X = Cl, Br, I). It is shown that such enhancement is not only due to the specific cubic antiperovskite structure of Na 3 OBH 4 but also because of the rotation of BH 4 cluster anion. This work deepens the understanding of the antiperovskite structure and the role of cluster anions for superionic conduction.