Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (11): 2029-2035.doi: 10.3866/PKU.WHXB201509231


Laser-Induced Fluorescence Spectra of the Photolyzed Products of C2H5SSC2H5 by 266 nm Laser

Hai-Yan. HAO,Zhen. LIU,Li-Li. ZU*()   

  • Received:2015-07-20 Published:2015-11-13
  • Contact: Li-Li. ZU
  • Supported by:
    the National Natural Science Foundation of China(21373033, 21173024)


Organic sulfides are an atmospheric pollutant that photolyze in the atmosphere, causing additional pollution. The S―S bond exists not only in organic sulfides but also in some proteins such as L-cystine, and this bond is crucial to the bioactivity of this protein. In this work, we studied C2H5SSC2H5 photolysis at 266 nm, which is the quadruplicated frequency of the common Nd:YAG laser. The laser-induced fluorescence (LIF) spectra detected the photolyzed products, C2H5S radical. Our results show that the C2H5S radical was mainly created by dissociation of the S―S bond in C2H5SSC2H5. We determined the potential energy curves of the S―S, C―S, and C―C bonds in C2H5SSC2H5 at the B3LYP/6-311++G(d, p) level, finding that photolysis at 266 nm caused the S―S and C―S bonds of C2H5SSC2H5 to dissociate at the ground???2029-1??? state. Nevertheless, photolysis at 266 nm did not photolyze the C―C bond of C2H5SSC2H5. By optimizing the Cs geometry of the C2H5S radical at the???2029-1??? state and the???2029-2??? state, we determined the???2029-2???-???2029-1??? adiabatic transition energy at the CASSCF/6-311++G(d, p) level, and then studied the LIF spectra of the C2H5S radical. The main pathway is dissociation of the S―S bond of C2H5SSC2H5, though the C―S bond in a few C2H5SSC2H5 molecules did dissociate.

Key words: C2H5S radical, 266 nm photolysis, S―S bond dissociation, Adiabatic transition energy, LIF spectrum


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